Search for a proper issue and add a comment in it via API

Hi guys,

Is it possible to find exact issue (e.g. if issue has some specific tag in description) and add a comment in it via API? These two actions would like to perform in one API call.

Jira support suggested:
I believe you need to have a script for that. As scripting is not supported by Atlassian Support, you can raise it to our Developer Community. Our developer will help you with that.

If someone knows how to do that or any ideas please share! Thanks in advance.