@Kyung *****
You’re getting contradictory information because you’re not using the standard pathway, and that’s a fragile and brittle way to do things here. The way you are “supposed” to do it - that is, the pathway designed for it - is to get a 3 month non-O from home (which has reduced requirements), come to Thailand, setup the bank account on arrival, transfer in your money and let it season, then use that to get the long term visa extension. If you particularly need to do anything else, like you’ve already closed down your life at home and it would be very expensive to go home and start the process there, you’re outside the normal sequencing, and you really will need a visa agent to help you find a way that works. As a foreigner with (I assume) no Thai, you will struggle enormously to do non standard things without help here.