get https://api.rollbar.com/api/1/item_by_counter/
counter
must be an item counter for an item in the project. The counter can be found in URLs like https://rollbar.com/myaccount/myproject/items/456/
(456 is the counter).
The success response is a 301 redirect like this:
HTTP/1.1 301 Moved Permanently
Location: /api/1/item/272505123
{
"err": 0,
"result": {
"itemId": 272505123,
"path": "/api/1/item/272505123",
"uri": "/api/1/item/272505123"
}
}