You can go to My account and Create an API key
Create an API key for them to use. With the following, you want them to have access and be able to upload(write).
Copy the key, and give it to your DM
After this, they have to go into Foundry again, into a world -> Configure Settings -> Module settings -> The Forge
Here they would need to paste the/your API key.
Warning
You should not paste your own code in here. Only the other players or the DM.
