you buy a charger having 5V/3A. Not necessarily, you have to buy Nokia Charger. You can buy any charger but it should be a branded one. e.g., I am using Motorola Turbo Charger having rating 5V/3A. and it charges rapidly till 90%. After that, to charge remaining 10%, it takes 20 mins.
It charges rapidly (as you can see in the screenshot that I attached here) than the original Nokia Charger, for sure.
Even you can go for Asus Max Pro M1 charger. Only Adapter can be used, use the Nokia Type-C cable. This combination is also fine.