Replaced ignition now key won’t start my key

So I had to replace the ignition switch on my car..
come to find out I had to buy the whole part and
now that we switched it out it came with two keys
for new ignition we turn it and everything cranks on
but it won’t start battery is good my starter is good
but now I have a green key flashing at the top of my  
dash board that I’ve never seen before and my
current fob I had won’t even start the car please
help me