The fuel pump relay is integrated into the engine bay fuse box and is not a replaceable part,other than another fuse box.Very much doubt if that is the problem.

I'd be inclined to start by checking if there is power at the fuel pump first. If you're lucky, you may have a cover or grommet under the rear seat to access the wiring and check there is voltage there. There may be four wires going into the tank unit ? Use a voltmeter on the two larger diameter wires as these will be the power supply ( the thinner ones will be the fuel gauge sender ). If there's battery voltage there whilst cranking the engine, the in tank pump will have gone.

If there's no voltage, you'll need to check for a blown fuse or damaged / corroded connections or wiring. A wiring diagram will be required for a full diagnosis, or enlist the services of an auto electrician who is familiar with the system if you don't feel up to the task.

It could be that the crank sensor has failed as this'll cause the pump not to run. To find out you'll need to check for an RPM signal using diagnostic equipment and see if you get a signal when cranking.