October 4, 2020 has passed...

Nominet UK also uses EPP. These resources might help

https://registrars.nominet.uk/uk-namespace/registration-and-domain-management/registration-systems/list-api/
https://registrars.nominet.uk/uk-namespace/registration-and-domain-management/registration-systems/list-api/rest-api/
https://registrars.nominet.uk/uk-namespace/registration-and-domain-management/registration-systems/epp/
https://registrars.nominet.uk/faq/what-are-the-differences-between-nominet-epp-and-standard-epp/

https://sourceforge.net/projects/nominetepp/

Whmcs has this

https://marketplace.whmcs.com/product/2822-generic-epp-registrar-module-for-generic-registries

The module is on Github

https://github.com/XPanel

Wisecp documentation and sample module

https://dev.wisecp.com/en/kbc/domain-name-operations
https://github.com/wisecp/sample-registrar-module