Cannot create non-global annotations even when targeting "panelId"

#1

I was following this link which describes how to create annotations:

Testing sake, postman was used to post annotations, i can see them in Grafana but it is showing up on all the panels.

I have two panels in the dashboard with dashboardId = 38
(1) panelid = 2
(2) panelid = 4

It supposed to show up itself only on “panelId”:4 as per my json body.
Am i missing something?

{
“dashboardId”:38,
“panelId”:4,
“time”:1557932161635,
“isRegion”:true,
“timeEnd”:1557932169205,
“tags”:[“deploy”,“production”],
“text”:“Annotation Description 4”
}

I want to know whether it is possible or not.
Refer post and issues: