website_event/views/event_registration_views.xml

<?xml version="1.0"?>
<odoo><data>
    <record id="event_registration_action_from_visitor" model="ir.actions.act_window">
        <field name="name">Registrations</field>
        <field name="res_model">event.registration</field>
        <field name="view_mode">kanban,tree,form</field>
        <field name="domain">[('visitor_id', 'in', [active_id])]</field>
        <field name="help" type="html">
            <p class="o_view_nocontent_empty_folder">
                No registration linked to this visitor
            </p>
        </field>
    </record>

    <record id="event_registration_view_form" model="ir.ui.view">
        <field name="name">event.registration.view.form.inherit.online</field>
        <field name="model">event.registration</field>
        <field name="inherit_id" ref="event.view_event_registration_form"/>
        <field name="arch" type="xml">
            <xpath expr="//field[@name='phone']" position="after">
                <field name="visitor_id" groups="base.group_no_one"/>
            </xpath>
            <sheet position="inside">
                <notebook>
                    <page string="Questions" name="questions">
                        <field name="registration_answer_ids" widget="one2many">
                            <tree editable="bottom">
                                <field name="event_id" column_invisible="True" />
                                <field name="question_id" domain="[('event_id', '=', event_id)]" options="{'no_create': True}" />
                                <field name="question_type" string="Type" />
                                <field name="value_answer_id"
                                    invisible="question_type != 'simple_choice'"
                                    domain="[('question_id', '=', question_id)]" options="{'no_create': True}"/>
                                <field name="value_text_box" invisible="question_type == 'simple_choice'" />
                            </tree>
                            <kanban class="o_kanban_mobile" create="false" delete="false">
                                <field name="event_id"/>
                                <field name="question_id"/>
                                <field name="question_type"/>
                                <field name="value_answer_id"/>
                                <field name="value_text_box"/>

                                <templates>
                                    <t t-name="kanban-box">
                                        <div class="d-flex flex-column justify-content-between">
                                            <div class="o_kanban_record_title oe_kanban_details">
                                                <strong>
                                                    <field name="question_id" domain="[('event_id', '=', event_id)]"/>
                                                </strong>
                                            </div>
                                            <field name="value_answer_id"
                                                invisible="question_type != 'simple_choice'"
                                                domain="[('question_id', '=', question_id)]" options="{'no_create': True}"/>
                                            <field name="value_text_box"
                                                invisible="question_type == 'simple_choice'"/>
                                        </div>
                                    </t>
                                </templates>
                            </kanban>
                        </field>
                    </page>
                </notebook>
            </sheet>
        </field>
    </record>

    <record id="event_registration_view_tree" model="ir.ui.view">
        <field name="name">event.registration.view.tree.inherit.online</field>
        <field name="model">event.registration</field>
        <field name="inherit_id" ref="event.view_event_registration_tree"/>
        <field name="arch" type="xml">
            <xpath expr="//field[@name='partner_id']" position="after">
                <field name="visitor_id" optional="hide" groups="base.group_no_one"/>
            </xpath>
            <field name="state" position="before">
                <field name="registration_answer_ids" string="Selected Answers" widget="many2many_tags" optional="hide" readonly="1"/>
            </field>
        </field>
    </record>

    <record id="event_registration_view_kanban" model="ir.ui.view">
        <field name="name">event.registration.kanban.inherit.online</field>
        <field name="model">event.registration</field>
        <field name="inherit_id" ref="event.event_registration_view_kanban"/>
        <field name="arch" type="xml">
            <xpath expr="//div[@id='event_ticket_id']" position="before">
                <field name="registration_answer_choice_ids" class="mt-1" widget="many2many_tags"/>
            </xpath>
        </field>
    </record>

    <record id="event_registration_view_search" model="ir.ui.view">
        <field name="name">event.registration.view.search.inherit.online</field>
        <field name="model">event.registration</field>
        <field name="inherit_id" ref="event.view_registration_search"/>
        <field name="arch" type="xml">
            <field name="partner_id" position="after">
                <field name="registration_answer_ids" string="Selected Answers"/>
            </field>
        </field>
    </record>
</data></odoo>