Hi Valeria, I've been a member of the Upwork community for quite a few years now and how never received any emails with promo codes. I've just upgraded to a paid account for the first time ever and want to make sure I am signed up to receive the emails when they are sent out.
Three years since Upwork took over odesk/elance without a single code makes it feel pretty unlikely that I will ever receive one and seriously make sme doubt they are actually being distributed. I've never came across a single Upworker who claims to have received one themselves.
Membership promo codes are offers given to Upwork freelancers and agencies via email, events, and partnerships. Unfortunately, we are unable to issue one of them via the Community. Thank you.