I just did that the other week.
Here's the link:
https://www.fb.gv.at/Pruefungen/pruefungen-flug.html // Direct link to form ->
https://www.fb.gv.at/dam/jcr:7d86a8f...nung%20(2).pdf
Sorry, but i couldn't find an english version.
Once i sent it in, i received an email the next day informing me it was accepted and i had a PDF with a copy of the validation... which was honestly not very impressive ;-). I hope to get the the other stuff i sent in back in the mail.. who knows.