It depends. For those who have only one name (either the given or family name), filling out online forms can be complicated. Depending on your nationality and other specific circumstances, there are different ways to solve the issue and complete your Thai eVisa application.
Writing “unknown” or repeating your name twice are just a few of the options, but the best idea to make sure you avoid further problems is to send us a picture of your passport so that we can evaluate the situation. Ultimately, your passport’s barcode and the Thai visa form will have to match.