Docker: ONLYOFFICE not reached. Please contact admin external access

Hello, i have a problem with error Docker: ONLYOFFICE not reached. Please contact admin.

I have a docker with onlyoffice and snap Nextcloud on the same VM.
On the VM all work is great nextcloud and onlyoffice is working. In settings of onlyoffice in nextcloud i write my INTERNAL IP. In settings of router i set ports forwarding. So external (by internet) nextcloud cloud is OK, onnlyoffice is ok (onlyoffice is running), when i go to external ip + port number.

But when i want to open document i have an error Docker: ONLYOFFICE not reached. Please contact admin](Docker: ONLYOFFICE not reached. Please contact admin).

So, i want its working external, what should i do? maybe set external ip in setting of onlyoffice? but its also error cURL error 7: Failed to connect to externalip port 443: Connection refused.

Please help me