It’s working for me once I remove the max_counter argument and add the missing self.radius to the object:
class Pi_LeibnizClass:
    def __init__(self, n):
        numerator = 4
        denominator = 1
        self.value_of_pi = 0
        counter = 0
        self.radius = 1
    
        while counter < n:
            nextterm = numerator/denominator * (-1)**counter
            self.value_of_pi += nextterm
            denominator += 2
            counter += 1

    def get_circumference(self):
        """Displays calculated value of the circumference of a circle."""
        return (self.value_of_pi) * (self.radius) * 2
        
    def get_area(self):
        """Displays calculated value of the area of a circle."""
        return (self.value_of_pi) * (self.radius) ** 2
    
    def get_volume(self):
        """Displays calculated value of the volume of a sphere."""
        return 4 / 3 * (self.value_of_pi) * (self.radius) ** 3
    
    def get_surfacearea (self):
        """Displays calculated value of the surface area of a sphere."""
        return 4 * (self.value_of_pi) * (self.radius) ** 2


def main():
    Leibniz_object = Pi_LeibnizClass(10)
    circumference = Leibniz_object.get_circumference()
    print (circumference)
    area = Leibniz_object.get_area()
    print (area)
    volume = Leibniz_object.get_volume()
    print (volume)
    surface = Leibniz_object.get_surfacearea()
    print (surface)