Don’t you have a 110 volt tub? So the electrical hookup was plugging the tub in?
Actually the Hotspring 110AC spa runs on a 20-amp circuit so HS includes a special single-outlet 20-amp waterproof box large enough to handle the GFCI so yes my dealer had to pull off the original outlet and rewire the electrical box for the new single outlet box. No not the most complicated install, I could have certainly done it myself. But I know some states won't let you even do this simple swapout when it comes to hot tubs.
I do know my dealer does wire 220v/60amp tubs as well at no charge assuming electrical has been run to the location. I was originally going to go 220 but I really had no need in my climate. I lose maybe a degree over a 30+ minute soak with the jets running and heater off