We're in the same boat- 2018 Outlander PHEV GT purchased used in 2023. Didn't have the password anywhere in the documentation that came with the vehicle (only one key too). Asked at the dealer yesterday when I brought it in for the 45K service and they wanted $225US to reset the WiFi module...
We only had the one key that came with the car (2018 GT purchased from a dealer in 2023) and wanted another for obvious reasons so purchased an OEM online. After talking to several independent auto key companies that were either mobile or close by I learned that it was unique enough in the car...
Don't have anything to add but want to thank you for posting this- we just picked up a 2018 GT with 31K miles and think the SOH may not be great (getting about 15 miles on a full charge for flat city driving with little or no accessories running).
Did not know about Watchdog, but already have...