Broken City water

[KiRyah]

I have a 2017 Keystone Montana 3910fb. The other day where the house connects was spraying water every where. I'm thinking about replacing it with this one.

Renator RV Water Inlet Connection. RV City Water Inlet With Check Valve. RV Water Fill Inlet. RV Water Hose Connector, City Water Fill RV. Water Hose Flange. City Water Hookup For Camper (white).

https://www.amazon.com/dp/B09W8DW44F?starsLeft=1&ref_=cm_sw_r_apan_dp_ANPW1P Q4V1W158HM6PAY

Does anyone have any ideas on what I'm missing?

Thanks in advance ☺️

[Martian]

Possible missing washer???