Which is different from is normally called a tourist visa, the (at the moment) 60 day exempt on arrival.
Key Points about the 90-day Non-Immigrant Visa:
Purpose:
Intended for those engaging in activities like business, education, or retirement.
Initial Stay:
Grants an initial stay of up to 90 days from the date of entry.
Extension:
Can be converted to a longer-term visa, such as a one-year Non-Immigrant Visa for retirement, marriage, or education, by applying for an extension through the Thai Immigration Bureau.
Application:
Can be applied for at a Thai Embassy or Consulate, through the Thailand E-Visa portal, or by mail.
There is a 60 day tourist visa, commonly referred to and known as visa exempt entry, that you can extend for 30 days as you have stated.
But there is also a 90 day non immigration visa...
Key Points about the 90-day Non-Immigrant Visa:
Purpose:
Intended for those engaging in activities like business, education, or retirement.
Initial Stay:
Grants an initial stay of up to 90 days from the date of entry.
Extension:
Can be converted to a longer-term visa, such as a one-year Non-Immigrant Visa for retirement, marriage, or education, by applying for an extension through the Thai Immigration Bureau.
Application:
Can be applied for at a Thai Embassy or Consulate, through the Thailand E-Visa portal, or by mail.