Can I use a 65w charger for MacBook Air (M1, 2020)

Presumably you mean an Apple 65w USB-C Power Adaptor …

… if so it’s completely safe; the device will only “draw” as much power from the adaptor as it needs to operate - and if necessary - charge while operating.

The corollary to that is that it will NOT charge your MBA significantly faster than the 30w adaptor which was originally included in the box.

About Apple USB power adapters - Apple Support explains "If your Mac uses USB-C to charge, you can charge your Mac laptop with any USB-C power adapter or display."

(emphasis added)

Inadvertent dupe deleted.