In order to disconnect Hashtag Expert with Facebook:
● Open Facebook (desktop browser).
● Click on the profile icon/photo.
● Tap Settings & privacy.
● Tap Settings.
Now on the same page, you'll see Business Integrations.
● Tap Business Integrations.
● Now a new page will pop where you can see all the existing integrations.
● Tap "Remove" to unlink Hashtag Expert from your Facebook.