I tried to put my phone in thai language before. I ask Samsung support, they answered that I would able to do with next update. CANNOT!
The worst part of this is that, if you buy a Note 9 in Thailand you can set any languages you need : including Canada French or Canada English.
You have another canadian exclusive here again. How lucky are we.
Please follow the below steps to change the language to thai :
Open settings >> general management >> language and input >> language >> add language >> tap on three dots at top right >> add languages >> scroll down and select the language as shown in the below image.
The 3.5 mm jack has been removed to pursue additional values. By deleting the 3.5 mm jack, the device improves a design perfection allowing the slimmest Note device of 7.9 mm. And, it allows expanding battery capacity. However, you may purchase type C to 3.5 MM jack convertor.