I sent a LTC to your address, the amount is big! I do not know how to get it back
You need to explain a little bit more about your problem. To which address you sent your LTC?
3H6RQQthC5HV1BUYT38NpF9CJVgJzVkubp
I sent a coin to this address 3H6RQQthC5HV1BUYT38NpF9CJVgJzVkubp, I have a key from this address, but I do not know what to do with it and how to cancel the transfer