To map priority to other systems prio use a groovy variable.
In this case we will send 1-kristisk when High is used to BC Jira.
def prio = "" switch(issue.priority.name){ case "High": prio = "1-kritisk" break; case "Medium": prio = "2-medium" break; default: prio = "Low" break; } return prio
Access the variable in your Action body
{ "fields": { "project": { "id": "10100" }, "summary": "{{issue.summary}}", "issuetype": { "id": "10001" }, "priority":{ "name":"{{BC_PRIO}}" }, "labels": [ "from_testsup" ], "description": "{{issue.description}}", "customfield_10600": "{{issue.customfield_10703}}", "customfield_10201": "{{issue.key}}" } }