Can my friend apply for a 90-day Non-B business visa for Thailand without a letter from the Ministry of Labour?

My friend is director of a company in Thailand but wants to start working so needs to get a 90 day non B business visa.

They have all documentation except a letter from the ministry of labour.

They were going to go to immigration in Singapore but were told they need the letter to get the visa there and they have to go to Hong Kong.

Is there anywhere else closer they can go without the letter from the ministry of labour and still get the 90 day non B business visa? KL, Cambodia, yangon, kota bharu etc? Thanks