account_payment_order: communication required in form view

account_payment_order/models/account_payment_line.py

@@ -67,6 +67,10 @@ class AccountPaymentLine(models.Model):
         check_company=True,
     )
     date = fields.Date(string="Payment Date")
+    # communication field is required=False because we don't want to block
+    # the creation of lines from move/invoices when communication is empty
+    # This field is required in the form view and there is an error message
+    # when going from draft to confirm if the field is empty
     communication = fields.Char(
         required=False, help="Label of the payment that will be seen by the destinee"
     )

account_payment_order/views/account_payment_line.xml

@@ -30,7 +30,7 @@
                         />
                         <field name="bank_account_required" invisible="1" />
                         <field name="communication_type" />
-                        <field name="communication" />
+                        <field name="communication" required="1" />
                     </group>
                     <group name="right">
                         <field