I admit that I haven't paid much attention to TSS in the past. I think maybe Strava calculates it if you are a subscriber? But I don't subscribe, so it doesn't calculate or display it. However, there is an external web calculator that I found that will peer into your Strava data and calculate your TSS scores
Strava TSS Calculator
I know nothing else about this site, and so caveat emptor.
Apparently, my normal training load at the moment is about 700/week. I can't say that I"ve lost much weight recently, though.