curl --request PATCH \
  --url https://api.lemlist.com/api/campaigns/{campaignId}/senders/{userId} \
  --header 'Authorization: Basic <encoded-value>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "channels": [
    {
      "type": "whatsapp",
      "id": "uwa_A1b2C3d4E5f6G7h8Q",
      "enabled": true
    },
    {
      "type": "email",
      "id": "usm_A1b2C3d4E5f6G7h8P",
      "alias": "hello@example.com"
    }
  ]
}
'

import requests

url = "https://api.lemlist.com/api/campaigns/{campaignId}/senders/{userId}"

payload = { "channels": [
        {
            "type": "whatsapp",
            "id": "uwa_A1b2C3d4E5f6G7h8Q",
            "enabled": True
        },
        {
            "type": "email",
            "id": "usm_A1b2C3d4E5f6G7h8P",
            "alias": "hello@example.com"
        }
    ] }
headers = {
    "Authorization": "Basic <encoded-value>",
    "Content-Type": "application/json"
}

response = requests.patch(url, json=payload, headers=headers)

print(response.text)

const options = {
  method: 'PATCH',
  headers: {Authorization: 'Basic <encoded-value>', 'Content-Type': 'application/json'},
  body: JSON.stringify({
    channels: [
      {type: 'whatsapp', id: 'uwa_A1b2C3d4E5f6G7h8Q', enabled: true},
      {type: 'email', id: 'usm_A1b2C3d4E5f6G7h8P', alias: 'hello@example.com'}
    ]
  })
};

fetch('https://api.lemlist.com/api/campaigns/{campaignId}/senders/{userId}', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

require 'uri'
require 'net/http'

url = URI("https://api.lemlist.com/api/campaigns/{campaignId}/senders/{userId}")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Patch.new(url)
request["Authorization"] = 'Basic <encoded-value>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"channels\": [\n    {\n      \"type\": \"whatsapp\",\n      \"id\": \"uwa_A1b2C3d4E5f6G7h8Q\",\n      \"enabled\": true\n    },\n    {\n      \"type\": \"email\",\n      \"id\": \"usm_A1b2C3d4E5f6G7h8P\",\n      \"alias\": \"hello@example.com\"\n    }\n  ]\n}"

response = http.request(request)
puts response.read_body

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://api.lemlist.com/api/campaigns/{campaignId}/senders/{userId}",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "PATCH",
  CURLOPT_POSTFIELDS => json_encode([
    'channels' => [
        [
                'type' => 'whatsapp',
                'id' => 'uwa_A1b2C3d4E5f6G7h8Q',
                'enabled' => true
        ],
        [
                'type' => 'email',
                'id' => 'usm_A1b2C3d4E5f6G7h8P',
                'alias' => 'hello@example.com'
        ]
    ]
  ]),
  CURLOPT_HTTPHEADER => [
    "Authorization: Basic <encoded-value>",
    "Content-Type: application/json"
  ],
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

{
  "data": {
    "campaignId": "cam_A1b2C3d4E5f6G7h8M",
    "senderStrategy": "random",
    "espMatching": false,
    "readOnly": false,
    "senders": [
      {
        "userId": "usr_A1b2C3d4E5f6G7h8K",
        "name": "John Doe",
        "email": "john@example.com",
        "channels": [
          {
            "type": "email",
            "id": "usm_A1b2C3d4E5f6G7h8L",
            "label": "john@example.com",
            "alias": "john@example.com",
            "esp": "google",
            "diagnostics": []
          }
        ],
        "diagnostics": []
      },
      {
        "userId": "usr_A1b2C3d4E5f6G7h8N",
        "name": "Jane Smith",
        "email": "jane@example.com",
        "channels": [
          {
            "type": "email",
            "id": "usm_A1b2C3d4E5f6G7h8P",
            "label": "jane@example.com",
            "alias": "hello@example.com",
            "esp": "microsoft",
            "diagnostics": []
          },
          {
            "type": "whatsapp",
            "id": "uwa_A1b2C3d4E5f6G7h8Q",
            "label": "+15550100199",
            "diagnostics": []
          }
        ],
        "diagnostics": []
      }
    ],
    "diagnostics": []
  }
}

{
  "error": "LinkedIn cannot be disabled alone. Remove the sender from the campaign instead",
  "code": "SENDER_CAMPAIGN_LINKEDIN_IMPLICIT"
}

The authentication you supplied is incorrect

route is available starting emailPro plan

{
  "error": "Campaign not found",
  "code": "SENDER_CAMPAIGN_NOT_FOUND"
}

{
  "error": "Route bad method",
  "code": "ROUTE_BAD_METHOD"
}

{
  "error": "The campaign uses a dynamic sender strategy: the leads select the senders",
  "code": "SENDER_CAMPAIGN_DYNAMIC_STRATEGY"
}