Firebase does not work (i don get the problem...)

Hello,
To illustrate it, see the picture below.
It should be like this:
After clicking on the button it should check if the name (TextBox1) is already taken. If so, should a message come, if not, the data from TextBox1 and TextBox2 be stored and then should open another screen.

However, after clicking on the button, I only have the progress dialog and it will not go away, as if it would not get a response from the server, but all data regarding the server is correct.

PS: I had ‘copied’ the building blocks from another app because I did not know how it works. Now I understand it, but it still does not work …
(In the other app everything worked fine)

Put the dismiss progress dialog block after everything, as it doesn’t show the dialog before that block, it’s closing the phones soul not the dialog.