This project is based on Alpine Linux, the official nginx image and an nginx module that provides static and dynamic brotli compression. Brotli and the nginx brotli module are built by Google. This project also adds GeoIP2 module to NGINX to allow capturing information from the client IP address in variables, using the MaxMind GeoIP2 databases, with the GeoIP2 dynamic module.
As this project is based on the official nginx image look for instructions there. In addition to the standard configuration directives, you'll be able to use the brotli module specific ones, see here for official documentation