How does Python's super() work without call directly?

I'm on Python and I'm checking and comparing my understanding with ready-made code on the internet. I'm familiar with the concepts of inheritance but I ran into some code here that confused me!

Although it uses inheritance, I don't understand where it calls the _call function! These functions seem to be called and executed somewhere other than user code.Can someone help me understand it؟

a simple example of inheritance :

class one(object):
  def __init__(self,a,b):
    self.a = a
    self.b = b

  def _call(self):
    return self.a + self.b

class two(one):
  def __init__(self,a,b,c):
    super(two,self).__init__(a,b)
    self.c = c

  def _call_(self):
    print(self.c * self.c)

used super() to call the init() of the One class

mt = two(1,2,3)
print(mt._call())