If you have the means, I suggest declining this interview. This is disrespectful to the candidates and speaks to a lack of care on the part of the hiring company.

That said, I recognize that you may not be in a position to decline, so I’ll give the best advice I can. The closest I have done is a set of coding exercises while on the phone with a recruiter, but they knew nothing about the coding exercises - they were basically just on the call to supervise. I wasn’t recorded on video, but the text editor and audio were recorded. It was intensely uncomfortable and felt like I was talking to myself the whole time, and I ended up stumbling all over myself trying to explain with zero feedback, trying to ask clarifying questions to the recruiter and getting “I’m sorry, I don’t know” every time. The only thing I can think of that would have really helped is to practice monologueing while doing hackerrank problems.