What are the financial requirements and procedures for applying for a Non-Immigrant Visa Category O-A from the US?

I have read many of the post in this group and they have mainly been about people in Thailand or in neighboring countries getting a visa.

My questions : I am in the US and want to apply for a Non-Immigrant Visa Category “O-A” (long stay). I have gone to the Thai Embassy website and read the requirements. I understand that I will need a medical form and a criminal record.

The requirements about the finance is puzzling. Does the 800K THB need to be in a Thai bank since I am not applying in Thailand.

Do I need to go to Thailand and open an account and transfer the money for the US to the Thai bank. Is so, how would I prove that the money is in the account and most important, how would I be able to open the account.

Thanks in advance.