Getting the relevant PCR tests required when travelling to the Phuket Sandbox

I am currently looking to go to the Phuket Sandbox before travelling to my house in Thailand 

I have been browsing websites but for some reason found limited options 

I was wondering what the best process is for  satisfying COE requirements as far as PCR Covid test go 

1) Do I have to book these

2) are there hotels that can book the tests as part of your reservation 

3) do you have to travel to the PCR facilities  -   and pay for the travel 

4) can anybody recommend or send me a link of where I can get the cheapest available PCR tests 

any info about this process would be much appreciated