On your older posts you mention UK and therefore I presume you were travelling to the UK. You could have got a Antigen for a cheap price and much quicker. In Bangkok they even have at the airport in 15 mins but I presume you were travelling from Phuket, so not sure down there. I did Antigen at a hospital and got certificate within a couple of hours as I had to wait for the Doc to arrive to sign it off, otherwise would have been quicker.
I heard Ethiad require PCR according to their policy, so make sure to check with the airline. Once at the UK there seems to be no checks, so its mainly for check-in
I got the Antigen before travelling on Qatar. I wouldn't be waiting until I got to the airport, but I did see that there is a 15 min results with certificate advertised at Swampy. I don't know anyone that has used it though
You mean, you missed the day it should have been or you have not yet got to the 2nd PCR? I can see a lot of tourists not doing it as why risk the holiday. I saw one lady tested positive, no symptoms and now locked up for 10 days of her holiday.
I was with Qatar and they just follow arriving countries requirements at this time if only transit. So according to the UK regulations in the link above, it's still Antigen (ATK) with certification to show at check in. Arriving to UK there are no checks.
I did the Antigen test which I think that's lateral flow. I did mine at hospital called Samitivej Srinakarin. Took 2 hrs and cost I think 500 for the test and the Dr fee to sign it off for the certificate 800 bht.