NS8 Collabora file load problem

Collabora is properly installed in NS8 and is active.
It is integrated in Nextcloud with access config OK.
But Collabora cannot load any file. In the log it says:
ERR loading document exception: Access denied, 403.
WOPI::CheckFileInfo failed on: https://cloud.hassun.xyz/index.php/apps/richdocuments/wopi/files/479366_ocpzsgr3kvfo?
Does anybody know how to solve this?

Moin Ralph,

have you entered the network you are accessing from in the Allow List for WOPI requests?

Regards…

Uwe

Moin,
you are right, that’s the point. It works after emptying this config field.
But I don’t get what the correct configuration looks like. Nextcloud and Collabora are on the same server behind the same firewall.
Would you mind to give me an hand for this?