Hi everyone, everything fine?

Odoo 12:

I have a Tree View of a custom module, I needed to add an item to change the status in bulk in my action dropdown.

So far so good:

      <act_window id = "id_for_record"
                    name = "Construction - Change Status"
                    src_model = "construction"
                    res_model = "construction.change.state"
                    view_type = "form" view_mode = "form"
                    key2 = "client_action_multi"
                    
        />

<record id = "wizard_view" model = "ir.ui.view">
            <field name = "name"> Test </field>
            <field name = "model"> construction.change.state </field>
            <field name = "arch" type = "xml">
                <form string = "Test">
                    <group>
                        <group>
                            <field name = "state"> </field>
                        </group>
                    </group>
                    <footer>
                        <button string = "Apply" name = "action_apply" type = "object" class = "btn-primary" />
                        <button string = "Cancel" class = "btn-default" special = "cancel" />
                    </footer>
                </form>
            </field>
        </record>

I added a model:

class constructionChangeState (models.TransientModel):
    _name = 'construction.change.state'
    state = fields.Selection ([('finalized', 'Finalized'), ('progress', 'In Progress')], string = 'State')


    def action_apply (self):
        pass

My problem is quite simple actually, how can I pass the selected Ids in the Tree View to the Form and make the bulk change?