A payment link on the invoice; paid comes back by itself.
Built, but not yet tested against the real service. It is switched on only after that test.
Still needed: a test in Mollie's test mode, with a test payment and a refund.
With your own Mollie key every invoice gets a payment link in the email and in the customer portal. When the customer pays, the invoice is marked paid by itself. If a part payment or credit note is added later, Trajenda replaces the link with a new one for the right amount.