GET /2/users/by/username/:username

      (async () => {
  try {
    const usernameLookup = await twitterClient.users.findUserByUsername(
      //The Twitter username (handle) of the user.
      "TwitterDev"
    );
    console.dir(usernameLookup, {
      depth: null,
    });
  } catch (error) {
    console.log(error);
  }
})();

    

      (async () => {
  try {
    const usernameLookup = await twitterClient.users.findUserByUsername(
      //The Twitter username (handle) of the user.
      "TwitterDev"
      {
        //A comma separated list of User fields to display
        "user.fields": ["created_at"],
        
        //A comma separated list of Tweet fields to display.
        "tweet.fields": ["created_at"],
        
        //A comma separated list of fields to expand
        expansions: ["pinned_tweet_id"]
      }
    );
    console.dir(usernameLookup, {
      depth: null,
    });
  } catch (error) {
    console.log(error);
  }
})();

    

      // Set the params values

// String | Required. A username.
String username = "TwitterDev";

try {
    SingleUserLookupResponse result = apiInstance.users().findUserByUsername(username, null, null, null);
    System.out.println(result);
} catch (ApiException e) {
    System.err.println("Exception when calling UsersApi#findUserByUsername");
    System.err.println("Status code: " + e.getCode());
    System.err.println("Reason: " + e.getResponseBody());
    System.err.println("Response headers: " + e.getResponseHeaders());
    e.printStackTrace();
}

    

      // Set the params values

// String | Required. A username.
String username = "TwitterDev";

// Set<String> | A comma separated list of fields to expand.
Set<String> expansions = new HashSet<>(Arrays.asList("pinned_tweet_id"));

// Set<String> | A comma separated list of Tweet fields to display.
Set<String> tweetFields = new HashSet<>(Arrays.asList("created_at"));

// Set<String> | A comma separated list of User fields to display.
Set<String> userFields = new HashSet<>(Arrays.asList("created_at"));

try {
    SingleUserLookupResponse result = apiInstance.users().findUserByUsername(username, expansions, tweetFields, userFields);
    System.out.println(result);
} catch (ApiException e) {
    System.err.println("Exception when calling UsersApi#findUserByUsername");
    System.err.println("Status code: " + e.getCode());
    System.err.println("Reason: " + e.getResponseBody());
    System.err.println("Response headers: " + e.getResponseHeaders());
    e.printStackTrace();
}