Yes, the Apple 11 can be charged with 20W fast.
However, the iPhone 11 does not come with a standard fast charge head and a fast charge cable, and is still a traditional USB-A lightning cable and 5W charging head. So if you want to charge the iPhone 11 fast, you need to buy a PD charging head and USB C to lightning cable.
The Apple 11 can be charged with 20W, but the charge is 18w, and I'm using it.