I had several problems. Ended up on a page to confirm my data, but no confirm button.
So I emailed a FileMaker employer, I know and got another link.
Maybe contact your FBA contact?
You profile description indicates you are in India. It looks like the FMI Web Store no longer supports in country purchases for India. I believe that is why the 'FBA Purchase Link' does nothing. You will have to contact your local FBA representative, Winsoft.