TRX is a rigid band that doesn't stretch. You set the "resistance" by the angle of gravity relative to the band.
A TRX push-up puts less load on the primary path than a conventional push up but is very challenging to all the other muscles that it takes to not flop over when you do it
These days I'd trust AMZN less than Temu. At least Temu and sellers on Temu still want to win your trust. AMZN thinks they have it and will still think they have it long after it's lost.
https://gofit.net/collections/resistance-tubes-bands
There are plenty of cheaper no-name options on Amazon, but they have the property that the handles snap off during use, risking injury.