Use the following settings for HLS Push:
Ingestion server: https://a.upload.youtube.com/http_upload_hls?cid=crmp-9fcz-fdzz-9k72-fkrj©=0&file=file.m3u8
Segment filename: /http_upload_hls?cid=crmp-9fcz-fdzz-9k72-fkrj©=0&file=file_%03d.ts
The bold text has to be replaced with your stream key available in YT studio.
The list size in CamStreamer App settings should be set to 5 based on YT documentation.
YouTube studio settings
More details can be found here: https://developers.google.com/youtube/v3/live/guides/hls-ingestion