My alliance send me coordinates but I can't use my free teleport item... help me please?

The free teleport takes you to the boss of your alliance, you cannot chose where it takes you. For this there is the advanced teleport available at your alliance shop.

You must select the menu, the briefcase, click the alliance teleport, and accept the location it places you. You can't just click the place in the map near the alliance, that requires you to spend diamonds. If you try moving the alliance teleport, it will require you spend diamonds, so just approve the first place it puts you. There are ways around it if you don't like the spot it wants to place you. Have someone camp were you don't want to go, and it will take you to the next available location.