Navigate to Fiverr's website and log in with your current username and password.
Click on your profile icon or username in the top right corner, then select "Settings" from the dropdown menu.
In the Settings menu, navigate to the "Account" tab. Find the option to edit your username and click on it.
Enter your desired new username in the provided field. Ensure it meets Fiverr's username requirements.
After entering your new username, save the changes. You may be prompted to re-enter your password for security purposes.