This achievement is pretty straight forward. Once you land on Tatooine for the All Worlds Ultimate Swoop Rally event and start as any of the teams, you can turn around and beeline North-West to the Sarlacc Pit!
I suggest picking Horizon’s Razor team as they go the fastest by default.

As you hop on your bike to race, before going to the starting line, turn around and head for the Sarlacc, as you approach the monster a small ramp should pop in on the side that you came from. Doing it this way will stop you from failing the Swoop Daily bonus for running out of time.
Taking yourself up the ramp will shoot you across the entire length of the Sarlacc and earn you the achievement “Sorry, Sarlacc” in the process.

If you still need help, I suggest this nifty guide by RemusGT: