To find it definitively:
1. Consult your owner's manual: This is the best place to start. It should have a diagram showing the location of fuses and relays.
2. Check the fuse box diagram: Even without the manual, the fuse box cover usually has a diagram printed on it. This might identify the flasher relay's location within the box or nearby.
3. Look for a small, square relay: If the diagram isn't helpful, visually inspect the area around the fuse box under the dash. The flasher relay is typically smaller than most other relays in the area.
4. Use a test light or multimeter (if comfortable): If you can't locate it visually, and have the necessary tools and know-how, you could test the circuit to trace the relay. This is recommended only if you are comfortable working with automotive electrical systems.
Remember to disconnect the negative battery cable before working on any electrical components in your car.