I am in Phuket now via the Sandbox process. You need to apply for a certificate of entry for the Phuket Sandbox model through a Thai Embassy or approved consulate (USA - LA, NYC, Chicago or Washington). The process takes 2 - 3 weeks if you already have a visa and entry stamp. Add an additional week if you need a visa. Basically you need the following to apply for the COE: current passport with at least 6 months validity, entry Visa, $100,000 USD Covid-19 travel insurance policy (issued online by a approved Thai insurance company, links on the embassy websites), vaccination certificate with approved vaccines, hotel booking direct with SHA + hotel in Phuket (you cannot book with any travel website like Agoda. It has to be direct with the hotel as they have to issue you a certificate with registration number needed for the COE application), direct flight into Phuket from outside Thailand (you cannot transit through Bangkok), fully paid invoice from the SHA + approved hotel for 14 days, separate fully pre-paid invoice from the hotel for three Covid PCR tests, and confirmed roundtrip airport/hotel transportation arranged by the hotel. Once you get your COE, you have to obtain an RT-PCR test not more than 72 hours before your flight departure time. The entire COE process is done online unless you need to send your passport into a consulate for a visa. Make sure all documentation is 100% correct as it is highly scrutinized during the application process, at the airport and upon arrival in Phuket. One little mistake and you might get rejected at any of the steps. Good luck !! https://www.thaicgny.com/entering-thailand/