yes I done the Phuket sandbox and you have to book and pre pay for 2 ofthem then you get the confirmation and you put that info on the application for the COE. if it does revert back to that system, quite easy
It's ok I done it last October, covid test at the airport then a sha + taxi to your hotel when you get the test results back you can go about as normal. after 7 days and two more PCR Tests you get the all-clear and get out of jail pass, then you can go about all over Good luck