Unable to perform dashboard test on remote server

I have installed docker images of openvidu 2.12 and kms on a remote server
when i tried to test the connection from dashboard i got this error

polyfills.a1c943ce5ec41b78581a.js:1 POST https://OPENVIDUAPP:test@domain.com:4443/api/sessions net::ERR_NAME_NOT_RESOLVED

can anyone help?