Nextcloud + Collabora(docker)

I install Collabora from docker with apache proxy as in this manual, but I have a problem…
For example “Failed to load Collabora Online - please try again later”
Where I can see detailed logs for trublshuting?

maybe this because I used mod_alias from my nextcloud?

Please set the loglevel to 1 in config/config.php for nextcloud and also to debug in /etc/loolwsd/loolwsd.xml in collabora to find more details.

Common mostly mistakes are domain setting in collabora docker image, ssl config and / or security settings for ip addresses.

Another thing you can try is setting name aliases for both of them in Docker and pointing both of them at the reverse proxy.