Seperating sets?

https://en.numista.com/catalogue/set.php?id=482
 

This set contains both P and D coins together, I just have the denver set, Is there a separate listing or can we add a verient for P and another varient for D? Im not sure how the coin sets work with logging

The 2021 American innovation proof set is also missing I think. Any advice on how to add a set instead of a single coin?

The US Mint has with only one exception (https://en.numista.com/catalogue/set.php?id=5873) never released a mint set consisting of only the Denver or Philadelphia mints.  The official sets contain both.  Creating a set with only half the coins is technically a third party set and not allowed.

If the 2021 American innovation proof set was issued by the mint you can create the Set yourself.  Pick one of the coins and use the Register a set with this type link at the bottom of the page.