Want to know which charger is best baseus 25w or ugreen 25watt for samsung a55?

I bought a charger for a55 from samsung store but i doubted that its a first copy, the problem is when i connect for charging "superfast charging" shows only at the time of connection but after phone starts charging only "Charging" is written all the...

Can someone mention where to find original samsung 25 watt charger for A55 phone model and its price also.