https://github.com/projectdiscovery/uncover/blob/main/uncover/agent/fofa/fofa.go#L17

I guess you are planning to use domain field to represent the result domain name information, but in FOFA domain field represents the primary domain name of the target.

Example, when the result is: api.baidu.com, then domain value of the field is baidu.com. If a user wants to query all Baidu domain names in FOFA, your way of writing will only return one record baidu.com.

You should use the host field in the FOFA API to represent domain information.