Change App Availability

My app is only available in some regions. During one of the review versions, the reviewer asked to remove accessibility from one of the countries or provide documents that allow to conduct activities in this country. At that time, there was no such document and I removed the availability in this country. Now - I have a document that confirms that I can conduct activities in this country. Availability is a separate section and is not related to versioning. How and where do I request app availability in a specific country?