How to implement epic link and spring autocompletion

We would like to implement create issue screen with autocompletion for Epic Links and Sprints fields like on Jira Software create issue screen:

But the following urls (used by Jira) are not whitelisted for JWT requests (returns 403):

Available analogs and doesn’t support “query” parameter for keyword filtering.

Should I brutforce all possible epics and sprints or there is more human alternative to filter required epics/sprints by keyword?