The Git Integration for Jira app automatically configures web linking for GitHub git repositories.
For single repository connections, web link setup is optional. However, git links will become available in Git Commits tab when configured.
For more information on this feature, see Documentation: Web linking.
More related articles on integration basics
Connecting to a git host account via Add new integration panel
Connecting to a single git repository (HTTPS | SSH)
Setting up web links (this page)