PlanetHoster Registrar Module allows you to register, renew, transfer and manage domain names at PlanetHoster through WHMCS. The first step to getting started is to become a registered domain name reseller with PlanetHoster. This is free, and can either be done with an existing logged in account by clicking on the "Reseller" tab in our client area @ https://my.planethoster.net/ and activating your domain name reseller account. Alternatively, if you don't have an existing PlanetHoster account, you can create a new account @ https://my.planethoster.net/en/client-area/new-client. After your account is created and you're logged in, you can then follow the previous step to activate your reseller account.
The best place to start if you need help with a specific product is to contact the developer. All WHMCS Marketplace developers have both a website and support URL listed.
The OpenSRS Domains Pro module allows you to register, renew and transfer domains from an ever-expanding selection of TLDs, including many new gTLDs. This module supports domain locking and WHOIS Privacy for select TLDs, as well as WHMCS Domain Sync.
Official GoDaddy Wholesale Domain Registrar Module
The ISPAPI Registrar Module connects WHMCS to your HEXONET account.
High-performance Domain Availability Checks using Hexonet's registrar API
Advanced domain module for WHMCS - Offer over 1000 TLDs to your customers