We have setup our GitHub Issues with the following schema

RITM000001-SCTASK0000001-My Short Description
<RequestItemNumber>-<CatalogTaskNumber>-<ShortDescription>

If the user provides the Request Item and not the CatalogTask number in the Title of the GitHub issue. How can that be used to add a new CatalogTask to that RITM when synced. Also how do you then update the GitHub Issue with the new CatalogTask Number.

If the GitHub Issue Title contains only the CatalogTask Number then the associated CatalogTask should be updated.

If no RITM or SCTASK entered then no sync should be created.

Here is what I have so far on the incoming sync for 

if(firstSync){
    entityType = "sc_task"
    if(replica.request_item?.contains("RITM"))
    {
        if(replica.catalogTask?.contains("SCTASK")){
            catalogTask.key = replica.catalogTask
        }
        else
        {
            // ???
        }
    }
}

To manage the CatalogTask number and RequestItem number I am maintaining the values through the sync process.

On The Outgoing SNOW I have a custom field named titleID which is populated by the following
the Entity is a CatalogTask

 replica.titleID = catalogTask.request_item.display_value + "-" + entity.key + "-"