suite/project_acceptance/views/project_portal_templates.xml

<?xml version="1.0" encoding="utf-8"?>
<odoo>

    <template id="portal_my_task_inherit" inherit_id="project.portal_my_task">
        <xpath expr="//div[@class='mt32']" position="before">

            <!-- modal relative to the actions accept -->
            <!-- <div role="dialog" class="modal fade" id="modalaccept">
                <div class="modal-dialog">
                    <form id="accept" method="POST" t-att-data-order-id="task.id" t-att-data-token="task.access_token" class="js_accept_json modal-content js_website_submit_form">
                        <input type="hidden" name="csrf_token" t-att-value="request.csrf_token()"/>
                        <header class="modal-header">
                            <h4 class="modal-title">Validate Task</h4>
                            <button type="button" class="close" data-dismiss="modal" aria-label="Close">×</button>
                        </header>
                        <main class="modal-body" id="sign-dialog">
                            <p>
                                <span>By signing this proposal, I agree to the task description:</span>
                                <ul>
                                    <li><span>Accepted on the behalf of:</span> <b t-field="task.partner_id.commercial_partner_id"/></li>
                                </ul>
                            </p>
                            <t t-call="portal.signature_form">
                                <t t-set="call_url" t-value="task.get_portal_url(suffix='/accept')"/>
                                <t t-set="default_name" t-value="task.partner_id.name"/>
                            </t>
                        </main>
                    </form>
                </div>
            </div> -->

            <!-- modal relative to the action reject -->
            <!-- <div role="dialog" class="modal fade" id="modaldecline">
                <div class="modal-dialog">
                    <form id="decline" method="POST" t-attf-action="/my/task/#{task.id}/decline?access_token=#{task.access_token}" class="modal-content">
                        <input type="hidden" name="csrf_token" t-att-value="request.csrf_token()"/>
                        <header class="modal-header">
                            <h4 class="modal-title">Decline This Task</h4>
                            <button type="button" class="close" data-dismiss="modal" aria-label="Close">×</button>
                        </header>
                        <main class="modal-body">
                            <p>
                                Tell us why you are refusing this task, this will help us improve our services.
                            </p>
                            <textarea rows="4" name="decline_message" required="" placeholder="Your feedback..." class="form-control" />
                        </main>
                        <footer class="modal-footer">
                            <button type="submit" t-att-id="task.id" class="btn btn-danger"><i class="fa fa-times"></i> Decline</button>
                            <button type="button" class="btn btn-primary" data-dismiss="modal">Cancel</button>
                        </footer>
                    </form>
                </div>
            </div> -->

            <!-- <div t-if="task.stage_id.name == 'cancelled'" class="alert alert-danger alert-dismissable d-print-none" role="alert">
                <button type="button" class="close" data-dismiss="alert" aria-label="close">×</button>
                <strong>This task has been canceled.</strong> <a role="button" href="#discussion"><i class="fa fa-comment"/> Contact us to get.</a>
            </div> -->
            <div t-if="task.stage_id.requires_acceptance">
                <div class="row justify-content-center text-center d-print-none pt-1 pb-4">
                    <div class="col-sm-auto mt8">
                        <form id="accept" method="POST" t-attf-action="/my/task/#{task.id}/accept" enctype="multipart/form-data">
                            <input type="hidden" name="csrf_token" t-att-value="request.csrf_token()"/>
                            <button class="btn btn-primary" t-attf-href="#" style="color: #ffffff"><i class="fa fa-check"/> Accept</button>
                            <!-- <a role="button" class="btn btn-primary" data-toggle="modal" data-target="#modalaccept" href="#" style="color: #ffffff"><i class="fa fa-check"/> Accepted</a> -->
                        </form>
                    </div>            
                    <div class="col-sm-auto mt8">
                        <form id="decline" method="POST" t-attf-action="/my/task/#{task.id}/decline" enctype="multipart/form-data">
                            <input type="hidden" name="csrf_token" t-att-value="request.csrf_token()"/>
                            <button class="btn btn-danger" t-attf-href="#" style="color: #ffffff"> <i class="fa fa-stop-circle"/> Declined</button>
                            <!-- <a role="button" class="btn btn-danger" data-toggle="modal" data-target="#modaldecline" href="#" style="color: #ffffff"> <i class="fa fa-stop-circle"/> Declined</a> -->
                        </form>
                    </div>
                    <div class="col-sm-auto mt8">
                        <!-- <form id="decline" method="POST" t-attf-action="/my/task/#{task.id}/feedback" enctype="multipart/form-data">
                            <input type="hidden" name="csrf_token" t-att-value="request.csrf_token()"/> -->
                            <a role="button" class="btn btn-warning" href="#discussion" style="color: #ffffff"><i class="fa fa-comment"/> Feedback</a>
                            <!-- <a t-attf-href="#discussion">
                                <button class="btn btn-warning" style="color: #ffffff"><i class="fa fa-comment"/> Feedback</button>
                            </a>
                        </form> -->
                    </div>
                </div>
            </div>
        </xpath>
    </template>

</odoo>