You can check your cPanel username from hPanel or cPanel directly.
Option 1 - Hosting
You can find your username by opening Hosting → Manage tab:
Your username will be in the cPanel details section under "Your cPanel Username is:"
Option 2 - cPanel account
You can also check your cPanel username by accessing your cPanel account. Once there, username will be shown on the right section of your screen under General information:
That’s it! Now you know how to check your username on cPanel 😊
cPanel usernames cannot be changed