I play on PS3, and want to start speedrunning GTA, but I don't know how I could record both a timer and my PS3

I am looking to start speedrunning GTAV on PS3 (Best you're gonna get is Classic% dont @ me) and was wondering if I had to have video evidence included with the runs. I am unsure of how to do this since all I have is a Chromebook which cant run proper SR timers.