I have a slab foundation and need
To move the refrigerator water line
To the opposite wall can I run it
In the attic and how would I do it?

in the warm desert, yes. in cold zones like Minnesota, emphatically heck, no. water line has to be run in a temperate zone or it will freeze out and flood you.

you can cut a strip of drywall off walls, drill for flex line, run it from any likely location, put protector plates over those stud locations where you drilled in the water line, and rerock the wall.

do NOT use those laughable "saddle valves" that put holes in your pipes. run a half inch line over to the fridge, use the correct shutoff that goes down to a quarter-inch compression fitting, and then your fridge connection. saddle valves are against code in many places, and against common sense everywhere.

Can you run it behind cabinets to get where you need to?

It is on the other side of kitchen

up and over
you can tape a heat trace line to the pipe
its a wire that will keep the pipe warm
heat trace it and insulate it.