The connections are OK according to the schematic but I suspect you still have insufficient LED current.
Try this: disconnect pin 1 of the MOC3020 then link pin 1 directly to +5V. If that turns the triac on, your problem is lack of current from whatever drives the LED.
If your drive signal comes from an MCU, the logic high needed to provide enough current may not be reaching 5V.
If you have a voltmeter, tell us the voltage across pins 1 and 2 also the voltage from pin 2 to ground when it should be turned on.
Brian