error says: AuthCodeUsernameRetrievalError while authenticating salesforce org with VS Code

Try below solutions:

1. Disable any VPN if ON.
2. Clear browser cache
3. Use the most recent cli version
4. Make sure vs code open the expected url

https://developer.salesforce.com/docs/atlas.en-us.sfdx_dev.meta/sfdx_dev/sfdx_dev_troubleshoot_auth_errors.htm