PowerBI Dremio Custom connector through gateway


I am getting following error : |Dremio:|Connection string is not supported.|
Could you please let me know what exactly is the issue

Have you tried following our documentation on setting this up? https://docs.dremio.com/client-applications/microsoft-power-bi.html

Yes, I have already gone through it, however it explains only the Desktop part. Now I have already published it to aa.powerbi.com ( PowerBI server) and want to setup autorefresh using gateway. The gateway is showing status as connected , however the above screenshot of configuring the datasource on gateway is throwing error that “Connection string is not supported”
Has anyone tried to setup gateway using Dremio custom connector ?