Hello I will stay 90 days in thailand, I need visa. So I tried several times on thaievisa.Go.th but it bugs everytime on page 4 (supporting documents)

Is it the right website to request visa for 90 days?

If yes, can you help me please? I cannot fill up from question 7 to 12

Someone knows what's the problem with the thaievisa.go.th ??? I try to finish with my Visa application, I uploaded everything, filled everything. I try to do the proceed to payment... I choose the submit application by post, and nothing happening just a weird message pop up in the corner as you can see on the photo... What timeslot?? I want to do by post not in person.....Someone had the same problem?? What can I do now??