For security reasons, only one person per housing contract receives the invoices in the app. If there is someone else on the contract who also wants to receive the invoices in their app, the person with the invoices can share them with the other contract party.
If you have invoices in the app and wish to share them with another app user, follow these steps: Go to the Payment functionality in the app and select Share my invoices. Choose whom you want to share the invitation link with, and then complete the process. Note that both parties need to approve the sharing in their respective apps for it to be completed.