Do u just have to use a putter on the green or can you use another golf club?

Technically you do not have to use a putter. I have used a wedge if I am like over 80 feet from the hole, but I also use putters from off the green just practice and make sure you are confident with all your shots before you try anything new. Just on the side I do not recommend using anything but a putter on the green, it is such a tight lie that the ball will stop instantly when it comes down.