How ammonia is amphoteric give answer with equations?

Ammonia is amphoteric because it can act as both a Brønsted-Lowry acid and base. In an acid-base reaction, ammonia can donate a proton (H+) to act as an acid:

NH3 + H2O ⇌ NH4+ + OH-

And it can also accept a proton to act as a base:

NH3 + H+ ⇌ NH4+