1. Put RDR2-Start_save_backup.bat and RDR2-Stop_save_backup.bat files in C:\Users\*YOU\Documents\Rockstar Games\Red Dead Redemption 2\Profiles\E34DF3FA folder.
(*YOU is your username; the letters and numbers in the name of the last folder "E34DF3FA" are different and unique for everyone.)
* to find this folder, you can simply copy and paste this line into the address bar of your file explorer:
%userprofile%\Documents\Rockstar Games\Red Dead Redemption 2\Profiles

2. When the game is running, run RDR2-Start_save_backup.bat (you can do it directly from \E34DF3FA folder, or create a shortcut and drag it to your desktop, but remember you can run RDR2-Start_save_backup.bat only when the game is running, otherwise it will close immediately).

The bat file will create a copy of your autosave SRDR30015 called "SRDR30015_copy-1m", then after 1 minute will rename it to "SRDR30015_copy-2m" and create a fresh autosave copy SRDR30015_copy-1m, then after another minute will delete SRDR30015_copy-2m, rename SRDR30015_copy-1m to "SRDR30015_copy-2m" and create a new fresh autosave copy SRDR30015_copy-1m, then it will repeat this procedure every minute until you exit the game or stop the bat file by closing its cmd window or by running RDR2-Stop_save_backup.bat file (it can only run when RDR2-Start_save_backup.bat is running).

3. When something undesirable happens, you can roll back to a previous autosave – exit the game immediately, then delete the latest autosave SRDR30015 and rename SRDR30015_copy-1m to "SRDR30015". (If, coincidentally, the bat file has already copied the newest autosave before you closed it or exited the game, use SRDR30015_copy-2m instead.)

4. You can rename my batch files, if you want, but if you rename RDR2-Start_save_backup.bat, you should also update its name in the RDR2-Stop_save_backup.bat script - right click on it and select "Edit", it will open in Notepad, change the "RDR2-Stop_save_backup.bat" to your new name and save the file.