In order to identify which license key you are using for your FSX 2018 / FSX 2020 software you will need to follow the steps below:
1. From your windows desktop, locate and right click on the FSX 2018 / FSX 2020 Icon
2. Select "OPEN FILE LOCATION"
3. Open the SYSTEM FOLDER
4. Open the FSXSetting File
5. If prompted, open with Microsoft Edge for a cleaner viewing experience. If this is not offered, the file will most likely open using Microsoft Notepad.
6. Now, locate the <activationCode> from the list. Highlight with your mouse and press both the ctrl + c buttons to copy the highlighted activation code. You may also write it down for reference.
7. You can now press both the ctrl + v button to paste it to a new location if you wish.