How can I list the uploads from a YouTube Channel?

Once you have the channel_id, change the highlighted letter as is shown:

Channel: Microsoft Hololens

Channel_id: UCT2rZIAL-zNqeK1OmLLUa6g

Uploads (playlist): UUT2rZIAL-zNqeK1OmLLUa6g

Once you have the uploads playlist, you can use this request for get the uploaded videos:

https://www.googleapis.com/youtube/v3/playlistItems?part=snippet%2CcontentDetails&playlistId=<UPLOAD_PLAYLIST_ID>&fields=items(contentDetails(videoId%2CvideoPublishedAt)%2Csnippet(publishedAt%2Ctitle))&key={YOUR_API_KEY}

And these are the results:

{
 "nextPageToken": "CAUQAA",
 "pageInfo": {
  "totalResults": 61,
  "resultsPerPage": 5
 },
 "items": [
  {
   "snippet": {
    "publishedAt": "2019-02-24T17:38:51.000Z",
    "title": "Industry Partner Solutions for Microsoft HoloLens 2"
   },
   "contentDetails": {
    "videoId": "FWYcuHUgcng",
    "videoPublishedAt": "2019-02-24T17:38:51.000Z"
   }
  },
  {
   "snippet": {
    "publishedAt": "2019-02-24T17:32:14.000Z",
    "title": "Introducing Microsoft HoloLens 2 (Audio Description)"
   },
   "contentDetails": {
    "videoId": "NtRGESjKT6M",
    "videoPublishedAt": "2019-02-24T17:32:14.000Z"
   }
  },
  {
   "snippet": {
    "publishedAt": "2019-02-24T17:31:30.000Z",
    "title": "Introducing Microsoft HoloLens 2"
   },
   "contentDetails": {
    "videoId": "eqFqtAJMtYE",
    "videoPublishedAt": "2019-02-24T17:31:30.000Z"
   }
  },
  {
   "snippet": {
    "publishedAt": "2019-02-24T17:39:08.000Z",
    "title": "PACCAR is exploring Dynamics 365 Guides and HoloLens 2 to improve employee onboarding"
   },
   "contentDetails": {
    "videoId": "OQDhTtDgir0",
    "videoPublishedAt": "2019-02-24T17:39:08.000Z"
   }
  },
  {
   "snippet": {
    "publishedAt": "2019-02-24T17:41:16.000Z",
    "title": "Introducing Dynamics 365 Guides for HoloLens 2"
   },
   "contentDetails": {
    "videoId": "V8c3pDKdHEc",
    "videoPublishedAt": "2019-02-24T17:41:16.000Z"
   }
  }
 ]
}

This is the Google API Explorer demo I made.

N.B, this channel has 61 uploaded videos and the maximun results per page are 50.

This is the entire working jsfiddle.