How to sign out of the app?
Method - 1
To sign out of the app
1. Open the Bigin app on your Mac.
2. Click Bigin in the menu bar that runs along the top of the screen.
3. Select Preferences in the dropdown to open Settings in Bigin.
4. Click the Sign Out 
button that's at the top left of the screen.
5. Select Sign out in the confirmation prompt to complete the action.
Alternatively,
Method - 2
To sign out of the app
1. Open the Bigin app on your Mac.
2. Click the profile information that is found at the bottom left of the screen.
3. Click the Sign Out 
button that's at the top left of the screen.
4. Select Sign out in the confirmation prompt to complete the action.