How can I get my subtask to be auto populate base on the item number in the parent card?

[Gisselle]

When I upload an issue I want the item number field to be tied to certain subtask or comments. 

[Mark Segall]

Hi @Gisselle and welcome to the community!

This should be possible, but need more context...

• Trigger - Are you expecting this to occur when a new issue is created?
• Condition(s) - Is this for a specific issue type, will all issue types have the item number field populated, etc.?
• Action(s) - Is it creating a subtask or updating one that already exists?  If there are multiple subtasks, is the expectation that all of them get updated or just those that meet certain criteria.  If certain criteria, what is that criteria.