It says the maximum current is 35 mA and, that would mean the transistor might be on-the-cusp of failing so, choose a more reasonable current like 5 mA and calculate a resistor value that's 1 kΩ. You could probably go as low as 1 mA with a 5 kΩ resistor.
But, there is a minor problem pointed out by @periblepsis; the minimum supply voltage for this device is 12 volts so, in effect, you'll have to use two resistors and form a potential divider like this: -
