For the most part, athletics clubs have little to do with entering individual athletes into sanctioned events, which usually occurs via the major sporting body or associated website and only after the athlete has been registered.
Some clubs or leagues running their own events have set up online entry to local events through their own websites.
Clubs can assist members in this regard by making them aware of when entry to particular events is available and by providing direct links to where online entry occurs via their website or through their social media pages.