How to add a new connection in Dynamic Host management using REST-API. Need the URI for same

Experts, could some one provide the rest uri for creating a new connection under Dynamic Host Management. I don’t see the rest documentation for the same.
I am running on - Checkmk Enterprise Edition 2.1.0p23

I’m also looking for this feature.
Is it not implemented yet?
Using checkmk 2.2.0p11 enterprise version

I’ve tried the following

curl -X 'POST' \
  --header "Authorization: Bearer $USERNAME $PASSWORD" \
  "$API_URL/domain-types/dcd/actions/fetch_phase_one/invoke" \
  -H 'accept: application/json' \
  -H 'Content-Type: application/json' \
  -d '{
  "site_id": "cmk",
  "connection_id": "dhc_test"
}'

however it failed with:

{“title”: “An exception occurred.”, “status”: 500, “detail”: “You are not logged into the remote site.”}

The same credentials work with other API calls.