Usually the P1 error indicates that dehumidifier needs to be defrosted. The unit has detected ice build-up on the condenser coils.
Unplug the dehumidifier for several hours. Then plug it back in. If the problem recurs, check that the fan that blows air across the coils is working properly. Make sure that the room is not colder than the operating range of the dehumidifier. If the problems continues to occur, you may have a refrigerant leak in the system. That will require a service call to repair the dehumidifier.
If the unit is under warranty, contact Westpointe. The manual I have for a Westpointe 65 PT dehumidifier, https://www.appliancefactoryparts.com/content/pdfs/136333-1.pdf,
indicates the unit is covered through year 5 after purchase for a refrigerant system. For Warranty service, the contact point is Midea Consumer Service at 1-866-646-4332. If the unit is not under warranty, consider whether to replace the dehumidifier.
I hope this helps.
(I have seen a dehumidifier develop a refrigerant leak. It constantly froze before the leak was repaired and the refrigerant topped off.)