Not enough info. In fact no info. So:
You can get a partial download, stop, then resume the download where you left off, if the server supports it. Use the same outfile name as first time
Code:
agent="Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:101.0) Gecko/20100101 Firefox/101.0"
#First time
curl -A "$agent" <url> -o OutFile.mp4
#Cut off here
#Resume where you left off
curl -A "$agent" -C - <url> -o OutFile.mp4