Alarm Goes Off When Trying to Start Land Rover Discovery 2003

Hi there,

It seems like my key is no longer recognized by my Rover. When I put it in
the door it wont lock or unlock and smoothly turns left and right without any
recognition. If I put the key into the ignition and turn it the alarm goes crazy
and the flashers come on (time is correct so the battery hasn't died) without
any attempt to start.

I tried the lock / unlock three times method on the drivers side door but it
still feels like the truck isn't recognizing the key.

Thoughts?

Thanks so much!