improve video quality for youtube

Hi, how can I improve I would like to upload zoom recordings to a youtube channel, but as we know the quality is reduced in zoom.  I only want to record myself.

I have a paid version of zoom, I have selected HD, I use a logitec brio 4k, so how can I get 1080p? 

Someone mentioned I can email zoom and they can adjust something from their side?? 

Any help appreciated. Pete