BNGHelp6 responded to you previously. Your license is showing as invalid because it was revoked or removed. You can try to get the system to update it by opening your Destiny 2 properties in Steam and going to the DLC tab. Uncheck Beyond Light and let it update to remove the installed key. Once it has finished updating, return there and then check it to reinstall the access key. If you still experience an issue, you'll need to contact Steam support because the license is not being properly granted to your account. The game's access reads your installed license access key, and if the access key is invalid, then the game will say you don't have access. The game relies on Valve's Steam license system, and Valve's Steam installation is what installs that license for access. Bungie cannot do anything on their end to force your license to be accepted.