Initiating a teams video call from an external application

My application has a video conference need. Currently I am using 3rd party library (like Dolby.io, Zoom, etc.,) to initiate a video call. I would like to initiate a video call using Teams from my web application.

I am using Graph APIs with calendar - event and also tried Online Meeting (in cloud communications) but I get stuck with forbidden / bad request or something.

Any one to help out on this?