It's usually a relay with a specific symbol or "FUEL PUMP" printed on it, or you may need to consult your owner's manual or a wiring diagram to identify it definitively. The fuse block itself might have a cover that needs to be removed for access. Look for a relay with multiple terminals and a number of similar-looking relays nearby.
Important Note: Always disconnect the negative battery terminal before working with any electrical components to prevent accidental shorts or injury.