const options = {
  method: 'PUT',
  headers: {'X-API-Key': '<api-key>', 'Content-Type': 'application/json'},
  body: JSON.stringify({list_entries: {blocklist: ['<string>'], safelist: ['<string>']}})
};

fetch('https://api.mailchannels.net/inbound/v1/users', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

import requests

url = "https://api.mailchannels.net/inbound/v1/users"

payload = { "list_entries": {
        "blocklist": ["<string>"],
        "safelist": ["<string>"]
    } }
headers = {
    "X-API-Key": "<api-key>",
    "Content-Type": "application/json"
}

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

print(response.text)

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://api.mailchannels.net/inbound/v1/users",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "PUT",
  CURLOPT_POSTFIELDS => json_encode([
    'list_entries' => [
        'blocklist' => [
                '<string>'
        ],
        'safelist' => [
                '<string>'
        ]
    ]
  ]),
  CURLOPT_HTTPHEADER => [
    "Content-Type: application/json",
    "X-API-Key: <api-key>"
  ],
]);

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

curl_close($curl);

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

curl --request PUT \
  --url https://api.mailchannels.net/inbound/v1/users \
  --header 'Content-Type: application/json' \
  --header 'X-API-Key: <api-key>' \
  --data '
{
  "list_entries": {
    "blocklist": [
      "<string>"
    ],
    "safelist": [
      "<string>"
    ]
  }
}
'

{
  "recipient": {
    "email_address": "<string>",
    "roles": [
      "<string>"
    ],
    "filter": true
  },
  "list_entries": [
    {
      "item": "<string>",
      "item_type": "<string>",
      "action": "<string>"
    }
  ]
}

{
  "errors": [
    "<string>"
  ],
  "code": 123,
  "message": "<string>"
}

{
  "errors": [
    "<string>"
  ],
  "code": 123,
  "message": "<string>"
}

{
  "errors": [
    "<string>"
  ],
  "code": 123,
  "message": "<string>"
}