Sorry, there is no SSD in these systems! Instead Apple solders the discrete Flash chips to the logic board, the control part is within the T2 chip and the data within the flash chips is encrypted with a unique key from the T2 chip.
So while you could desolder the Flash chips there is nothing to allow the data to be recovered directly from them.
Your only hope is to find someone with the skills to patch your system together long enough to copy off your stuff..