Before you can increase your usage limits beyond 1000 devices, you need to join Google's EMM Community.
The EMM Community is a private community for developers to access private documentation and guidance, post questions, and work with Google to bring your solution to market. As a member of the community, you'll also receive direct support from Google experts.
To join the community, follow these steps:
Try out the Android Management API. Take note of the Google Cloud project ID you use.
Fill out the interest form below. Include the project ID you used to test as well as some details about what you'd like to develop.