You don't say how old the car is. Failed central locking in a mature car used always to mean a wiring fault in the driver's door hinge area - where most of the flexing happens over many years. That may have nothing to do with the key itself, and unless you fancy fiddling with broken wires it may need a new loom :-) On the other hand there may just be a tired switch or contact somewhere else.

The chip in the key communicates to the immobiliser system via the transducer ring on the steering lock . If you can use your original fobs , and transfer the blades , then that should work . Think you’ll need to remove the airbag, steering wheel and switches to replace the lock which is attached by shear bolts .