First thing to check is the interlocks, in neutral? sidestand up? kill switch in run position? clutch lever pulled in?
If all that checks out ok, next to check is power to the starter relay when the starter button is pushed, is it making a click at the relay?
Is there no click at all? Put a jump cable across the relay terminals/posts and is the starter now cranking the engine?
If so, the relay or the live power to the relay has a fault.
If the starter engages when bridging the terminals, BUT will NOT engage when pushing the starter button you'll need to trace the fault back to the starter button.
All the testing must be done in a specific order of steps, it's important the tests are all done to ascertain the fault.
But then again, it may just be a loose or dirty ground terminal or positive terminal at the battery.
Check all the basic connections first.