@Kjetil ********
He's NOT 🚫 blacklisted. He was denied entry because of his recent history of staying in Thailand without a correct Thai Visa.
IF he applies for the DTV visa...
He needs as everyone else meet the requirements for it with the Thai Embassy or Consulate where the application is submitted using the Evisa online application system.
IF he doesn't get the DTV visa approved.. then that is a new problem for him.
Likely will be DENIED entry into Thailand. And have to buy a flight ✈️ ticket to his home country.
One possible option...
If not issued the DTV visa ...
Contact an experienced Fast Track Service Company to see if they can help get you stamped in for 60 days as Visa Exempt Entry.
If they agree to accept you, you will be met when you get off the arrival flight and guide you thru a Thai Immigration desk to get the New entry stamp in your passport.
Provide them your passport nation, and your recent history of being in Thailand, including the denied entry.
They are the largest border and Visa run service company in Thailand.
They also have Fast Track Service in most Thai airports with international flights arriving.