To reset your password or 2FA, go through the following steps:
config.js file in your Gunbot folder with a text editor like Notepad++
Scroll to the "GUI" section on the bottom of the file
Change the value for either
login (for password) or for
twoFA (for 2FA) to false.
Save the file and start and access Gunbot again, you will be able to setup a new password or 2FA code from there.