Update: I have solved the problem.
When I entered my AGI, I removed the minus sign. so, the AGI was 10.
The next part was whether or not I received a refund or owed money. The key here is to enter the actual money owed or reserved as listed on your 1040. Since I was claiming 2018, I had to check line 20a. I am not sure of the line you have to check if you owed money, but there is a question mark just about the space with the info. In my case, line 20a was 0.
To summarise:
-AGI 10 (remove minus)
-Refund amount (line 20a) 0
-Entered in banking information
The transaction was successful!
I hope this helps. It worked for me, so I would suggest clicking on the question marks as they will guide you.
Hope this helps.
