<record id="button_click_action" model="ir.actions.server">
    <field name="name">Button Action</field>
    <field name="binding_model_id" ref="project_name.model_res_partner" />
    <field name="model_id" ref="project_name.model_res_partner"/>
    <field name="state">code</field>
    <field name="code">action = model.my_function()</field>

   <field name="res_model">res.partner</field>
</record>

Project name like folder name(calendar).

I think it will helps you.

Thanks.