I'm presuming you mean an RT PCR test?

I can't advise you on that precise route, but I will make one suggestion : print out the relevant page(s) from the embassy pages to show your airline if questions arise.

@Steve ******

"it might be worth checking if the airline requires it". It will also be the airlines job to enforce the rules of where you're flying TO (not FROM).

You don't need any tests to LEAVE anywhere. What you might need is a covid test to ENTER your next destination. Check the website of your destination country. It might be worth checking if the airline requires it.

If entering visa exempt or any tourist visa, then you need a return or onward ticket.

@Kelvin *******

errrrr you do know that this post is about traditional Thai dancing?

10 seconds on Google

You shouldn't have issues. All airlines use TIMATIC, the aviation travel "bible", containing all visa and passport information for all countries (updated online every few days and in print, monthly). So long as the Thai authorities inform timatic of any changes, it'll be there. The staff might have the "old rules" in their memory and need to check. As mentioned above, screenshot the relevant info just in case.

@Gregory ********

yes

You can go into your bank back home and ask for a telegraphic transfer. To be honest, it's easier and cheaper to use the transferwise app (I think they recently changed name to "wise").