Many applications to join phab.lubuntu.me are from spammers, or people we have no details about (often using spoofed email accounts, eg. using an invalid @ubuntu.com or @lubuntu.me email - these are very easily verified).
The bar to join phab.lubuntu.me isn’t very high, as we’d welcome more people contributing to Lubuntu.
For people already involved with the Ubuntu project, I’ve usually found a request on this site (open or PM made about the time of the phab join request), or mention on IRC/telegram etc so the request is expected.
If I don’t know of any such explanatory request, a quick search online of the email/name provided is made where I expect to see some results when linked with ‘ubuntu’ or ‘lubuntu’ (or something related to open source, GNU/Linux etc).
Alas many requests for accounts only find banned from forum for spamming and like results in searches 
If you’d like to come help us, we’d love to have you. An explanatory request on this site may make applications to join phab & like development sites easier to accept.