That's is from their site not a Firefox browser issue here. You should contact their site on how to download and save files from the site so that you don't exceed your download quota.

i am trying to download files but they keep stopping the loading and i have to re download them because the option of retry is not available now i try again it says i cannot perform the download because it exceeds

The "download quota exceeded for this file, so you can't download it at present." may be due to the Google drive limitation for each day as a comment here says there can be a limit say 750Gb a day.