Before i dive in too deep, i just wanted to ask the community here if what i'm trying to achieve is possible.
Essentially, i want to create a tab on the entry PUBLISH page let's call it Extra. Then i want to take complete ownership of the contents of that tab and place a bunch of php code in there for some non-EE related functionality. I simply need to do this within a publish tab in EE to grab the entry_id while a user is editing it. I did this in EE2 via Accessories, but those have been deprecated since and i'm assuming this is an option.
Is this doable? OR can you suggest a way of doing this another way?