Using Shared File for Time Machine Backup between Two MacBooks

I'm attempting to backup my newer MacBook Pro (2019, 16-inch, Catalina 10.15.7) to a shared file folder on my old MacBook Pro (2011, 15-inch, Sierra 10.12.6). When setting up the shared file, it does not allow for me to select "Advanced Options" in order to set the folder for use with Time Machine. I was told that this is due to the destination Mac having Sierra and that this is only possible for Mojave, which is not supported on my older Mac. However, I have seen plenty of people doing this kind of backup on High Sierra systems. Would I be able to update this older mack to High Sierra and use the shared file folder as a Time Machine backup for my newer system? If not, what other workarounds are possible? Thanks!