Appwrite Function in Project A can not access database of Project B

I create a Appwirite function in Project A and an API Access Key in Project B. I have provided Secret key and all other Endpoint to the Appwrite Function but its is not able to access the Database of the other project. Can someone tell me what I am doing wrong? (See picture)

Is this against cloud or a self-hosted instance of Appwrite?

And what is happening? Are you getting some sort of error?