This is the documentation of JSU for Jira Cloud. If you are using JSU on Jira Server or on Jira Data Center, you can find the documentation here.
You must write the 'JQL Query' and choose one option about the number of issues found. For example:
With this precondition, the post function will be only executed for Bugs.
No more will you need a separate workflow (and special workflow scheme configuration), when you only want 1 post function to perform different for a particular issue type.
For information on how to configure workflows in JIRA, see the JIRA documentation.
See the JQL Use Cases for several examples.
How to write JQL Query
Supported Field Types