If the hub tells you that Meridian People & Skills Hub is available to accounts with a Jira or Confluence license, your account is not one the app serves: you have no skills profile, and colleagues do not find you in expert search.
Usually it is the product access on your account — a guest account, or one without a seat. The conditions, and how long a change takes to reach the app, are listed in Who takes part in the hub. Ask your Jira administrator to check yours against it.
This is not the same as declining Atlassian's access dialog, which produces a similar dead end from a different cause. See The app does not work after you declined the access dialog.