Full disclosure I'm attempting to rebuild a feat that has already been published but not scripted. The Base -I messaged them asking if they planned on scripting it I got no reply as of yet. -I'm using this for a game that I am in and I have no intention of publishing it unless this person does not plan to continue their development of their feat. In that case I will attempt to publish it.
This is what I have.
Now to the problems I'm having
I'm trying to add an eldritch Invocation AND Know how it's added in, -Now I got that to work by using the template for eldritch adept, But I have no idea where it inside the structure of the feat it is being added in/from.
For some reason under the prerequisites it's not allowing me to set a class level my only option is a level. I'm trying to figure out if I need to get something or buy a feat that has such a prerequisite to open up that option.
Now I've seen class features added I'm trying to figure out how to add specifically a warlock boon. Just like eldritch Invocation and as I seen with martial adept these things can add something that's not directly listed or obviously listed. How do I add such a thing?
Lastly is there a possibility of adding internal links for the things that are highlighted in the image, cuz right now they are external links tp DND Beyond's website.
Full disclosure I'm attempting to rebuild a feat that has already been published but not scripted.
The Base
-I messaged them asking if they planned on scripting it I got no reply as of yet.
-I'm using this for a game that I am in and I have no intention of publishing it unless this person does not plan to continue their development of their feat. In that case I will attempt to publish it.
This is what I have.

Now to the problems I'm having
-Now I got that to work by using the template for eldritch adept, But I have no idea where it inside the structure of the feat it is being added in/from.
1) It's hidden from us for some reason.
2) This type of prerequisite does not exist because feats have never been class-specific.
3) No such thing for specifically Pact Boon. It exists for Eldritch Invocation and Maneuvers, as you have noticed.
4) Not unless it is a few specific things (spells, action types, damage types, monsters, ...).
Thank You for Your time I will just have to build what part if the functions I can of that pact that I'm able too then.