Nextcloud + OnlyOffice behind Cloudflare Tunnel, no SSL

Hello, I do apologize for asking this question as it has been asked many times, but I don’t think my simple scenario applies and I’m relatively new at all of this so I’m easily confused. The setup that I have is Cloudflare Tunnel → Traefik → Nextcloud/OnlyOffice.

Both Nextcloud and OnlyOffice do not have a self-signed SSL, I can only access these two services through http when I’m in the network. The reason I took is this approach, aside from lack of knowledge, is that I am using Cloudflare’s SSL when accessing these services through the public domain. It seems redundant to locally add a SSL to Nexcloud and OnlyOffice. I “think” I am telling these two services “trust me, you are signed” with some settings.

I do have Nextcloud and OnlyOffice fully working, and I did manage to link them in Nextcloud → Administration → ONLYOFFICE, by using the public https OnlyOffice URL and the secret key.

Now, the problem. When I go to Nextcloud and create a new document, when the doc automatically opens, I get a “Download Failed” error. I checked the logs and there’s nothing in there.

Please help! Thank you.