Hi there!
If you have purchased a DLC and cannot access the content, please try restoring your licenses.
https://help.bungie.net/hc/en-us/articles/360049196071-Accessing-and-Restoring-Licenses-to-Destiny-Content
If the issue persists, please contact your platform's support team for further assistance in restoring your licenses, as they are the ones who manages your licenses.