With gate connected to emitter, it should be off - if not, it's dead.
The gate can be damaged quite easily by excess voltage, which is why they are supplied with a bridging link fitted.
The gate drive needs to switch between 0V and around 15V, with a decent current drive capability - and amp or two minimum - as the gate capacitance is high, listed at 36nF in the datasheet.
For fastest possible turnoff, the gate needs to go negative briefly.
If you just need a pulse at intervals, a relay switching between 0V and 15V and connected to the gate via a low value (eg. 3.3 Ohms) resistor, should work.
The average 15V current will be low, but add a large electrolytic and a parallel 0.1uF or larger film cap, to supply the brief high current pulse.
Connect a rather higher value resistor, eg. 1K, directly between emitter and gate to avoid any possibility of static charge building up on it, and leave that permanently connected.