The letter is a common “courtesy” letter. You do not have to answer it at all. It is a clue that pooling may be coming. You can choose to lease with Staghorn or with any other party that offers a lease. Would suggest getting a good oil and gas attorney to review any draft lease as most of them are not in the mineral owners’ favor and need some critical edits.
The location has already been approved for the well. Case 2022-003081. You should have gotten the mailings for the two cases that have been filed so far.
You can also wait for pooling. Many of us prefer that option and would pick the highest royalty. Derby Exploration is pooling in section 27 with a hearing scheduled for 10/25/22. The rates offered at that pooling will be in indicator of the competition in the area. You can compare to your offer.