OnePlus doesn’t release Full ROM zip Packages always. SO This Rom updates collections are must.
Also People who play with custom roms frequently or Root their Device.
They require Firmware and boot.img .
This website helps you To Find all your OnePlus devices updates Full Zip Packages.
Website – link
It has as old As Oneplus 3t to recently Oneplus 10pro and 10R Rom firmware collections.
Open that website Choose your Device variant and Your preferred Rom package .
And download the rom link via 1DM app to get Good download Speeds.