I got the same message after supporting the patreon and clicking the link. Is there another link to the 0.4 alpha?
You account isn't linked to patron at the moment, go into your contact settings and add your patron details and wait a little time,, you should be linked and be able to access it
If you only recently became a Patron, it won't show up before the end of the month, however. Enter your details as described above to make sure you are hooked up next month without delay.