curl --request PUT \
  --url https://cloud.memsource.com/web/api2/v1/projects/{projectUid}/customFields/{fieldInstanceUid} \
  --header 'Authorization: <api-key>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "selectedOptions": [
    {
      "uid": "3HYnHHLkTPJfMxBCDbPXFe"
    }
  ],
  "value": "<string>"
}
'

import requests

url = "https://cloud.memsource.com/web/api2/v1/projects/{projectUid}/customFields/{fieldInstanceUid}"

payload = {
    "selectedOptions": [{ "uid": "3HYnHHLkTPJfMxBCDbPXFe" }],
    "value": "<string>"
}
headers = {
    "Authorization": "<api-key>",
    "Content-Type": "application/json"
}

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

print(response.text)

const options = {
  method: 'PUT',
  headers: {Authorization: '<api-key>', 'Content-Type': 'application/json'},
  body: JSON.stringify({selectedOptions: [{uid: '3HYnHHLkTPJfMxBCDbPXFe'}], value: '<string>'})
};

fetch('https://cloud.memsource.com/web/api2/v1/projects/{projectUid}/customFields/{fieldInstanceUid}', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://cloud.memsource.com/web/api2/v1/projects/{projectUid}/customFields/{fieldInstanceUid}",
  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([
    'selectedOptions' => [
        [
                'uid' => '3HYnHHLkTPJfMxBCDbPXFe'
        ]
    ],
    'value' => '<string>'
  ]),
  CURLOPT_HTTPHEADER => [
    "Authorization: <api-key>",
    "Content-Type: application/json"
  ],
]);

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

curl_close($curl);

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

package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://cloud.memsource.com/web/api2/v1/projects/{projectUid}/customFields/{fieldInstanceUid}"

	payload := strings.NewReader("{\n  \"selectedOptions\": [\n    {\n      \"uid\": \"3HYnHHLkTPJfMxBCDbPXFe\"\n    }\n  ],\n  \"value\": \"<string>\"\n}")

	req, _ := http.NewRequest("PUT", url, payload)

	req.Header.Add("Authorization", "<api-key>")
	req.Header.Add("Content-Type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

HttpResponse<String> response = Unirest.put("https://cloud.memsource.com/web/api2/v1/projects/{projectUid}/customFields/{fieldInstanceUid}")
  .header("Authorization", "<api-key>")
  .header("Content-Type", "application/json")
  .body("{\n  \"selectedOptions\": [\n    {\n      \"uid\": \"3HYnHHLkTPJfMxBCDbPXFe\"\n    }\n  ],\n  \"value\": \"<string>\"\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://cloud.memsource.com/web/api2/v1/projects/{projectUid}/customFields/{fieldInstanceUid}")

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

request = Net::HTTP::Put.new(url)
request["Authorization"] = '<api-key>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"selectedOptions\": [\n    {\n      \"uid\": \"3HYnHHLkTPJfMxBCDbPXFe\"\n    }\n  ],\n  \"value\": \"<string>\"\n}"

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

{
  "createdAt": "2023-11-07T05:31:56Z",
  "createdBy": {
    "uid": "3HYnHHLkTPJfMxBCDbPXFe"
  },
  "customField": {
    "allowedEntities": [],
    "createdAt": "2023-11-07T05:31:56Z",
    "createdBy": {
      "email": "<string>",
      "firstName": "<string>",
      "id": "<string>",
      "lastName": "<string>",
      "uid": "<string>",
      "userName": "<string>"
    },
    "description": "<string>",
    "lastModified": "2023-11-07T05:31:56Z",
    "lastModifiedBy": {
      "email": "<string>",
      "firstName": "<string>",
      "id": "<string>",
      "lastName": "<string>",
      "uid": "<string>",
      "userName": "<string>"
    },
    "name": "<string>",
    "options": {
      "remainingCount": 123,
      "truncatedOptions": [
        {
          "deprecated": true,
          "uid": "<string>",
          "used": true,
          "value": "<string>"
        }
      ]
    },
    "required": true,
    "requiredFrom": "2023-11-07T05:31:56Z",
    "uid": "<string>"
  },
  "selectedOptions": [
    {
      "deprecated": true,
      "uid": "<string>",
      "used": true,
      "value": "<string>"
    }
  ],
  "uid": "<string>",
  "updatedAt": "2023-11-07T05:31:56Z",
  "updatedBy": {
    "uid": "3HYnHHLkTPJfMxBCDbPXFe"
  },
  "value": "<string>"
}