- (Edited)
PRO100CiRiLl Xiaomi uses different charging protocols on their phones and chargers, probably proprietary technology.
Charging is (oversimplified) a combination of Watts and Amperes. For example on my Nothing Phone 2a the maximum charging speed seems to happen at 27/28W with 8A. This is done with a Nothing 45W PD Charger. It supports PD 3.0 and PPS charging standards.
You don’t need an original Nothing charger but you should search for one that supports the standards mentioned above.