Missing Coolant Overflow Cap - '15 Street Triple R

Hey everyone, anyone know of a place I can source just the cap for the coolant overflow tank on my '15 Street Triple R? From my searches on the internet, looks like the part number is T2101015.

Anyone have a store online they like to purchase these from or any recommendations for good parts sources in the Bay Area, CA? I am new to the Triumph world so would appreciate any good recommendations.

Thanks!