I can no longer find my Passport in finder

Please shut down the computer, then physically disconnect the Passport and then re-plug in the Passport and restart. If the drive is still not recognized then it may have simply failed and needs to be replaced. All HD's die, if your WD if 5 years old or older there is a very good chance that is what has happened.

Please remember the WD Passports are not very high quality EHDs and have a high failure rate due to enclosure overheating. WD uses sealed enclosures meaning the internal HD does not get good cooling airflow to keep the HD cooler. Heat is one of the killers of electronics.

If you find the WD has failed please consider replacing with a high quality External Hard Disk such as the OWC Mercury Elite Pro. I have some that are close to 20 years old that still work just fine, the HD's have died over time however replacing the HD is a 5 minute job and only requires a simple screwdriver.

Open the application Disk Utility (in the folder Applications > Utilities). In the View menu, select "Show All Devices". Do you see your external drive in the sidebar?

Okay, by chance have you looked in Disk Utility (Applications- Utilities- Disk Utility) to see if the WD can be located? If it can then do things like checking the physical connections and trying new cables, if the drive cannot be found chances are it’s dead.