To use the IF function for two conditions in a cell, you can use the AND function within the IF function. Here are the steps to achieve the desired result:

1. Select cell A3 where you want to apply the IF function.
2. Type the following formula in the formula bar:
   
   
   Formula:

   =IF(AND(A1="ABC",A2=500),"50KGS","") 

3. Press Enter.

This formula checks if both conditions A1="ABC" and A2=500 are true using the AND function. If both conditions are true, then the formula returns "50KGS" in cell A3. If either of the conditions is false, then the formula returns an empty cell.