If you are a member of ALA/ACRL, you should already have access to ALA Connect using your normal ALA credentials.
Below are instructions on how to double-check that you are a member of HSIG Community within ALA Connect.
If you are not a member of ALA/ACRL, you can create a guest account within ALA Connect to participate in the HSIG. You do not have to join ALA/ACRL to participants in the HSIG ALA Connect Community.
Below are instructions on how to create an ALA Connect guest account. There is also a brief video you can watch below.