33 w。
Redmi Note9 Pro supports 33W fast charging and does not support wireless charging.
Redmi Note9 (5G version) supports 18W fast charging, and does not support wireless charging.
Redmi Note9 (4G version) supports 18W fast charge and OTG2.5W reverse charge.
Redmi Note9 series all do not support wireless charging, wired fast charging speed for most users is enough speed.
Redmi note9 supports 18w fast charge, and you will have no problem with a 66w charging bank. Redmi note9 can definitely use 66w, because the 66w charging bank also supports 18w fast charging, and there is no need to worry about the phone being charged.