%{issue.cfnnnnn}
issue?.customfield_nnnnn?.key
PRJ
{issue.cfnnnnn.id}
10100
A valid project ID
issue?.customfield_nnnnn?.id
Please note, that JWT DC returns the project name whereas JWT Cloud returns the project key. In order to receive the project name in JWT Cloud please use Project Picker (single project) - Name: %{issue.cfnnnnn.name}