Click on the Firefox menu.
Choose the item "Add-ons" and then left in the menu "Extensions".
On the overview page you can see all installed add-ons. The right side shows two buttons as choices. You can deactivate the add-on here or completely remove it.
Click on the corresponding button and you will receive the browser message about the successful Removal of the addon.
If the Ghosty symbol is still visible, restart the browser.
Click the menu field in the Chrome taskbar.
Go to "Extensions" via "More Tools". A new page will open. Search here for Ghosty and click on "Remove" on the Ghosty button.
If the Ghosty symbol is still visible, restart Chrome.