stock-rma/rma_refund_reason/wizard/rma_refund_view.xml

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

    <!-- Inherit Form View to Modify it -->
    <record id="view_rma_refund" model="ir.ui.view">
        <field name="name">rma.refund.form.view</field>
        <field name="model">rma.refund</field>
        <field name="priority">99</field>
        <field name="inherit_id" ref="rma_account.view_rma_refund" />
        <field name="arch" type="xml">
            <xpath expr="//field[@name='description']" position="replace">
                <field name="description" invisible="1" />
                <field
                    name="refund_reason_id"
                    options="{'no_create': True}"
                    required="1"
                />
            </xpath>
        </field>
    </record>

</odoo>