account-financial-tools/account_document_reversal/views/account_payment_view.xml

<?xml version="1.0" encoding="utf-8" ?>
<odoo>
    <record id="view_account_payment_form" model="ir.ui.view">
        <field name="name">view.account.payment.form</field>
        <field name="model">account.payment</field>
        <field name="inherit_id" ref="account.view_account_payment_form" />
        <field name="arch" type="xml">
            <field name="state" position="before">
                <field name="is_cancel_reversal" invisible="1" />
            </field>
            <button name="cancel" position="after">
                <button
                    name="cancel_reversal"
                    attrs="{'invisible': ['|', ('state', '!=', 'posted'), ('is_cancel_reversal', '=', False)]}"
                    string="Cancel"
                    type="object"
                />
            </button>
        </field>
    </record>
</odoo>