[RussEfarmer]

You can get OBS for free online then set it up like a shadow play and have a certain amount of time that it will record if you set up a keybind. Easy thing to use and install, just open it and set it up real quick then set it to like 60 seconds through 2:30 minutes and set a keybind to record the activity then and it will record it.

Rhapsody made a very nice thread about this a few years ago, currently stickied in the ban request section
(the thread says only OBS classic supports replay buffers, but that's not true anymore)