They will deliver it based on your home address you placed on petition. You will get an update from DHL with tracking number. It takes about one week from Issued to Delivery.
To answer your question. Each petition are processed as separate, individual petitions. The I-400 was processed according to its rules and regulations that do not pertain to I-751.
This is why we tell people that there is no such thing as a combo interview. Your local office does not have to do it. Until that has processed citizenship is on hold or supervisor will deny and you will have to refile after I-751 is approved. Also you cannot appeal the denial.
So you filed for I-751 in December2021 and filed for I-400 in April 2021.
When is your 2 year expiration date? Why did you file for I-400 before I-751?