An online unlocker does not "remove" the password. It performs a or Dictionary Attack using the server’s computing power. It tries millions of passwords per second until one fits.
Have you successfully used an online 7zip unlocker? Share your experience in the comments, but never share the file itself! 7zip password unlocker online free top
Did you save the password in Google Password Manager or Bitwarden? Search for "7z" there. An online unlocker does not "remove" the password