Error with code 400: USERNAME_INVALID

Description and reason:
No one is using this username, or the username is inappropriate.

Solution:

Remove the current @username from the list of recipients


Detailed description:

The "USERNAME_INVALID" error in Telegram occurs when using programs that interact with the Telegram API, such as messaging or automation tools. This error indicates that the entered username (@username) is invalid or cannot be used.

The main cause of this error is that the specified username does not exist or violates Telegram's rules. The Telegram API checks the validity and availability of each username, and if it does not meet the platform's standards, the "USERNAME_INVALID" error is returned. This can happen if the user enters a name with invalid characters, or if the username is already taken or has been deleted.

To resolve this error in the program, follow these steps:

Step 1: Remove the current @username from the recipient list. The program will not be able to send messages or perform actions until the invalid username is removed from the contact list.

Step 2: Verify the correctness of the username and ensure that it exists and is valid. You can check the username through Telegram’s official search to confirm that it is available for use.

The "USERNAME_INVALID" error is related to the restrictions imposed by the Telegram API, which strictly monitors the use of usernames. Ensure that you are entering correct and active usernames to avoid encountering such errors in the future.