Without this fix if a customer doesn't fill in the ZIP (which is not required) he/she will get the following error:
odoo.addons.payment_mollie_official.models.sale_order: ERROR! The following fields of the billingAddress are missing: postalCode
Gunther made a very similar PR but it has the phone and name included, which really shouldn't be done. Name is already required by default and we should not make a phone required as we technically don't need it. The phone part is already handled in another PR so the only thing that remains is the ZIP code.
Without this fix if a customer doesn't fill in the ZIP (which is not required) he/she will get the following error: odoo.addons.payment_mollie_official.models.sale_order: ERROR! The following fields of the billingAddress are missing: postalCode
Gunther made a very similar PR but it has the phone and name included, which really shouldn't be done. Name is already required by default and we should not make a phone required as we technically don't need it. The phone part is already handled in another PR so the only thing that remains is the ZIP code.