Welcome to Android Central forums. I don't have this unit and finding someone with this unit randomly on this site is pretty low but it won't stop us from trying to help you.
I wasn't able to find an exact screenshot for the WiFi set-up but I found the manual and in the manual I found this screenshot that shows an entry field and on-screen keyboard. It looks like there's more of the data box under the keyboard. Are you able to close the keyboard to see the full box?
View attachment 369949
There is also the possibility that you just need to press enter. What would the tick box even be to enable in this process?
Perhaps post a screenshot of your own showing this page and the message to give us a bit more to go on.
From everything I can find related to that part number it appears the device is manufactured in China, no surprise there, by EasyTone. I found their contact us page where you could reach out and ask them about this, they would know more and better than I.
Click here to visit that page.
I briefly surfed their site but could not find an FAQ page or any other place to post/ask a question.
Not sure how much we can really help but let us know what you find and we can continue from there.