Update account_payment.py

change_vat_in_partner/models/account_payment.py

@@ -8,7 +8,12 @@ class AccountPayment(models.Model):
     @api.model_create_multi
     def create(self, vals_list):
         vals = super().create(vals_list)
-        partner = self.env['account.move'].search([("name", "=", vals_list[0]["ref"])],limit=1)
-        if partner:
-            vals.partner_id = partner.partner_id
-        return vals
+        if type(vals_list) == dict and vals_list.get("ref"):
+            partner = self.env['account.move'].search([("name", "=", vals_list["ref"])],limit=1)
+            if partner:
+                vals["partner_id"] = partner.partner_id.id
+        elif type(vals_list) == list and vals_list[0].get("ref"):
+            partner = self.env['account.move'].search([("name", "=", vals_list[0]["ref"])],limit=1)
+            if partner:
+                vals[0]["partner_id"] = partner.partner_id.id
+        return vals