I want to make a Blazor application that can make video calls

ADefWebserver The Hero sample might be overkill to follow, it might be easier to look at the quickstart here: https://docs.microsoft.com/en-us/azure/communication-services/quickstarts/voice-video-calling/get-started-with-video-calling 

You'll need to interop to:

• Create the CallClient and CallAgent
• Init the DeviceManager
• Call callAgent.startCall()
• Respond to any event on the all (participant, or stream added)