In any case you feel there is a delay or any issues/ queries with the graduation process, you can always reach out to the developer support team and create a support ticket for assistance. They can take care of it.

@ajathar Tyler's recommendation is correct. The process that monitors apps and aggregates usage statistics that are used in the graduation process runs on a recurring basis. Therefore, it can sometimes take several hours for the system to recognize that you have met the stated graduation requirements.

Furthermore, @Tyler Liu's recommendation to create even more requests is a good one, as you need to make 20+ requests within a given time period, so that if you wait too long to check back, you may end up right back where you started. So make an over-abundance of API calls, and check back every hour until the "Apply for Production" button is enabled.