How to get list of reporters from the project in the jira rest api? How to search by displayName?

[Iurii Budnikov]

I found a doc how to get list of reporters. 
But it's not clear how to add a search query to the api.
For example I want to search by user's displayName

https://developer.atlassian.com/cloud/jira/platform/rest/v2/api-group-user-search/#api-rest-api-2-user-search-query-get

Thanks

[Iurii Budnikov]

My example of query is 
query?query=is+reporter+of+AG+AND+displayName+is+"test"
It returns an error Unable to parse UQL