class BillAdjustment(models.Model):
    _name = 'bill.adjustment'
    _description = 'Bill And Adjustment'
invoice_id = fields.Many2one('account.move', string='Invoice')
label_amount_ids = fields.One2many('bill.adjustment.items', 'bill_id', string='Label and Amount Lines')

def open_invoice_form(self):
    """Generate invoice for reservation payment"""
    account_move_obj = self.env["account.move"]
    for reservation in self:
        vals = {

            "move_type": "out_invoice",
        }
        invoice_line = []
        for line in reservation.label_amount_ids:
            invoice_line_vals = {
                "account_id": "",
                "quantity": 1.000,  # Assuming the quantity is always 1 for a reservation
            }
            invoice_line.append((0, 0, invoice_line_vals))

        if not invoice_line:
            raise UserError(
                _("Cannot create invoice without any invoice lines. Please add at least one invoice line."))

        vals.update({"invoice_line_ids": invoice_line})

        # Create the invoice
        account_invoice_id = self.env["account.move"].create(vals)
        account_invoice_id.action_post()

        # Open the invoice form view after creating the invoice
        invoice_obj = self.env.ref("account.view_move_form")
        return {
            "name": _("Generate Bill"),
            "view_mode": "form",
            "res_model": "account.move",
            "view_id": invoice_obj.id,
            "type": "ir.actions.act_window",
            "nodestroy": True,
            "target": "current",
            "res_id": account_invoice_id.id,
            "context": {},
        }

class JobSummaryItems(models.Model):
    _name = 'bill.adjustment.items'
    _description = 'Job Summary Items'bill_id = fields.Many2one('bill.adjustment', string='Bill Adjustment')

here i want when o click on open_invoice_formbutton then it take me to account.move model bill menu view but now wwhen i clcik on this it give me 

The field 'Customer' is required, please complete it to validate the Customer Invoice.


how i solve this 
if you know please help he
thanks