Migration with REST API problem

I have two versions of the same process which smal differ (in process ).
I´ve started 3 instances on the first version and tried to migrate with the standard command localhost: 8080 / engine-rest / migration / execute generate these 3 instances on the second version, but no changes appear on cockpit.
Delivery-41.bpmn (10.5 KB)
example.json (1.2 KB)

“migrationPlan”: {
“sourceProcessDefinitionId”: “Delivery:41:63427cd5-4d40-11ec-a05e-0050569f510d”,
“targetProcessDefinitionId”: “Delivery:42:63427cd5-4d40-11ec-a05e-0050569f510d”,
“instructions”: [
“sourceActivityIds”: [“Activity_419898998”],
“targetActivityIds”: [“Activity_419898998”]
“sourceActivityIds”: [“anEvent???”],
“targetActivityIds”: [“anotherEvent???”],
“updateEventTrigger”: true
“processInstanceIds”: [
“processInstanceQuery”: {
“processDefinitionId”: “Delivery:41:63427cd5-4d40-11ec-a05e-0050569f510d”
“skipCustomListeners”: false

Can someone give me some insights? Am I missing some steps?

How can I properly prepare an inquiry “Request Body”?