hai

how to pop up a existing module form after a button press?

def action_approve(self):
        self.state='approved'
        invoices=self.env['account.invoice'].create({
            'type': 'out_invoice',
            'partner_id': self.partner_id.id,
            'user_id': self.env.user.id,
            'admission_id': self.name ,
            'origin': self.name,
            'invoice_line_ids': [(0, 0, {
                'name': 'Invoice For Admission',
                'quantity': 1,
                'price_unit': 500,
                'account_id': 41,
            })],
        })

i need to display a form for invoice  created