If you have a free Google account, you have to use Google Takeout, which is cumbersome, but will let you keep your data if you lose access to your Google account.
This process has four steps:
The fourth step is recommended but not as necessary, if you chose to save the file to Dropbox, OneDrive or Box.
A paid for Google account (Google Suite/Workspace) lets you use backup software to backup. Instructions for specific devices/software: