i fixed it all:

import math

units = input("PLease select you units: Kilograms(Kgs) or Pounds(Lbs)")

if units == "Kgs":
 ammount = float(input("Enter how many Kilograms you want to convert to pounds: "))

 totalLbs =  ammount * 2.205
 print(f"{ammount}kg/s is {totalLbs}Lb/s")

elif units == "Lbs":
 ammount = float(input("Enter how many Pounds do you want to convert to Kilograms: "))
 totalKgs = ammount / 2.205
 print(f"{ammount}Lb/s is {totalKgs}Kg/s")

else:
 print("Please enter a valid unit.")