Open Discord and go to your server
Click the server name at the top left
Select Server Settings
Go to the Roles tab
Create a new role or edit an existing role
Set the role name to your guild tag
Save the changes
Assign the role to members who should have the tag
If your server uses a custom server tag feature, enable it in Server Settings if available
Make sure the tag is visible in member profiles or nicknames if your server settings allow it