1. Add relationship
POST https://www.arcgis.com/sharing/rest/content/users/{{username}}/addRelationship
Request Body
[{"name"=>"f", "value"=>"json", "datatype"=>"string"}, {"name"=>"originItemId", "value"=>"{{item_id}}", "datatype"=>"string"}, {"name"=>"destinationItemId", "value"=>"{{data_item}}", "datatype"=>"string"}, {"name"=>"relationshipType", "value"=>"APIKey2Item", "datatype"=>"string"}, {"name"=>"token", "value"=>"{{access_token}}", "datatype"=>"string"}]
RESPONSES
status: OK
{"success":true}