I'm apparently very bad at choosing site names or there's something wrong with that piece. Seems that no matter what I choose for a site name, I'm shown a message stating that I can't use that name.
I'm getting the exact same "error", and if I enter a new one and click "Create", it doesn't show anything different (even the error message states the previous name), but if I click the link to add pictures, it just opens a new tab with the same page... I believe this is still an unfinished product. A little more info would be much appreciated.
And just made a new blog post about plans for passwds.io, like opening up the source: https://longren.io/introducing-passwds-io/