Domain availability check Via Regiter API enable domain suggestion tool and configure its settings. Domain suggestions are based on domain registrars API. The tool will check for availability and provide clients with smart domain suggestions based on their initial search.

For domain suggestions to work properly you need to choose the domain module that support this feature. Currently this feature is supported by modules:

RRPProxy
Enom
OpenSRS
ResellerClub

hxxps://hostbill.atlassian.net/wiki/spaces/DOCS/pages/876052524/Domain+suggestions