Anonymous participant Please supply here exactly what it says under issuing authority

What does your passport say exactly under place of issue?

Anonymous participant 6 months is cutting it close these days. Times have changed and requirements are getting somewhat stringent. Possibly a cover letter along with your application stating your reasons for visiting, why this course , general interest in why you love Thailand, plans after finishing the course, and what you'll do with the remaining 4 years of the visa.

Manually edit the biodata info. Do not trust the OCR to read and fill the fields correctly, as warned about on the evisa application website. You can edit up until the time you submit. No mistakes are allowed for the biodata entry fields.

Course length?

@Ralph ******

so they buy a non O in Thailand.

No and no, you can enter from anywhere

@Tony *********

not necessarily true, the price is 2000 baht for non O, either way the OP would be in Thailand with a 90 day non O and trying to open a bank account.

@Kevin ********************

it's a document submission field in the evisa website form application.

Just before the visa expires a well timed entry (along with qualifying insurance) will get you another year stamp, so, almost 2 years out of that visa. After that final entry you'll need to buy a reentry permit to keep the current permitted to stay stamp.