If you are listing on .com and want to upload a video along with pictures, the size limit is 150MB, which is pretty tight. There may be a setting on your camera to film in a more compressed format, but it still does not give a lot of video run time for some items.
No Affiliation, but if your video is to big, I found this site very handy to reduce the size of mp4 videos https://www.freeconvert.com/video-compressor/download
It reduced the size by 42%, and you can then run the compressed file through it again and that file goes down by 42%.
