When publishing via RTMP, such as via ffmpeg or OBS, after you have provisioned your stream, you must then make the stream manager broadcast transcoding request, using the GUID of your stream provision:

http://{host}:{port}/streammanager/api/4.0/event/{scopeName}/{streamGUID}?action=broadcast&transcode=true

You will then need to broadcast the 1st level (highest) variant via RTMP.

For example, if your stream provision is:

https://streammanagerurl/streammanager/api/4.0/admin/event/meta/live/stream?accessToken=token

{
  "meta": {
      "authentication": {
      "username": "",
      "password": ""
     },
      "stream": [
        {
          "name": "stream_1",
          "level": "1",
          "properties": {
          "videoHeight": 720,
          "videoWidth": 1280,
          "videoBR": 2500000,
          "videoFPS": 24
          }
         },
                 {
          "name": "stream_2",
          "level": "2",
          "properties": {          
          "videoHeight": 360,
          "videoWidth": 640,
          "videoBR": 1000000,
          "videoFPS": 24
          }
         },
                 {
          "name": "stream_3",
          "level": "3",
          "properties": {          
          "videoHeight": 180,
          "videoWidth": 320,
          "videoBR": 500000,
          "videoFPS": 15
          }
         }
],
      "georules": {
      "regions": [
        ""
      ],
      "restricted": "false"
    },
    "qos": "3"
  }
}

Then your transcoder broadcast query would be: https://streammanagerurl/streammanager/api/4.0/event/live/stream?action=broadcast&transcode=true

and your rtmp target would be: rtmp://<transcoderip>/live/stream_1