The screenshot is asking for your current address in HCMC.

The Thai Consulate in HCMC appointment booking means nothing.

You can type anything & book any option.

1. Take a screenshot showing you have an appointment confirmed at the Consulate

2. When you arrive at the Thai Consulate in HCMC, simply show the security guard that you have an appointment at that day. (You can even go anytime that day)

I recommend taking a screenshot of the confirmed booking as the email often plays up & doesn't sent.

3. The security guard will allow you through to wait in line.

Inside the Thai staff don't go by any appointments or booking system, they simply serve each person as soon as they come to the window.