Error in implementing multithreading in a class

[srm]

Hello,
Just started learning multi threading concept in python as beginner..I want to print values
1 to 10 with two different functions using multithreading concept within a class ,my code is below:

import threading
class Class1:
    
   
    i=1
    j=1
    def f1():
       global i
       while i<=10:
            print(" I is now %d" %i)
            i=i+1
    def f2():
        global j 
        while j<=10:
            print("J is now %d" %j)
            j=j+1
    def Main1():
        t1=threading.Thread(target=f1())
        t2=threading.Thread(target=f2())
        t1.start()
        t2.start()
    
ob=Class1()

ob.Main1()

But getting error:

Error:
Traceback (most recent call last):
  File "C:/Threading1.py", line 26, in <module>
    ob.Main1()
TypeError: Main1() takes 0 positional arguments but 1 was given