MK42Dragon

We drove it from the UK to Spain. From there, we were prepping it to take the engine out but when we checked to make sure it ran fine, it wouldn't start. It originally cranked for a sec and then stopped. Now it doesn't even do that.

I have a 2004 Legacy with a EJ253 engine from the UK. A while back, I brought it back to Spain with me to use on another project I was working on. Since then, it has not been able to turn on. My friends and I thought that either the car keys were out of battery or the keys need to be reprogrammed because the remote will not unlock the car without physically inserting the key. We changed the batteries on the keys, but still nothing. Normally this wouldn't be an issue but this car appears to have an immobilizer. Is the immobilizer the problem, or just by chance, something else went bad when we arrived in Spain? For reference, I go back and forth from the UK and Spain, if there are any shops I could go to/ send parts. We really would like to solve this issue before we swap the engine into the other car. Any and all suggestions would be appreciated.