One of the Generic Zigbee Light drivers would be best for this device (one that matches the capabilities of the bulb, which I'm assuming does not do RGBW or color temperature). Unfortunately, I don't think any of these have a "flash" command built-in like many of the switch/dimmer drivers do. You could try the Generic Zigbee Dimmer driver, which does have a "flash" command (and give you level control that the similar switch driver lacks), but there may be some things that still don't 100% work with that driver given that it was not written for this specific type of device (though I don't really know what the differences would be).
Alternatively, if you're doing this flashing with a rule, you could simulate the same behavior with manual rule actions: capture bulb state, then send a series of delayed "on" and delayed "off" commands in a repeat however many times before restoring the bulb state. I don't know how the Generic Zigbee drivers work, but this is basically what the corresponding Generic Z-Wave drivers do for you behind the scenes. Many devices do not natively support flashing, so this is emulated with software (lots of Zigbee bulbs actually do but vary in implementation and usually don't indefinitely flash; I'm guessing Hubitat therefore doesn't poke into these capabilities), and whether you do it with an app or a driver won't really affect that outcome.
Speaking of "that outcome," I know you didn't specifically ask about this and might not want to hear it, but Cree bulbs are notoriously problematic on ZHA networks like Hubitat. (They are fine for some people if bulbs are only Zigbee devices on your network, as they might be if you use a hub dedicated for this purpose, and definitely fine if you use them on a ZLL network like with a Hue Bridge.) Here is one of many threads you can find on Cree bulbs in particular: Dealing with Zigbee Issues - Gotta love those Crees. However, this problem is common with many Zigbee bulbs, and the "Tips..." section of Hubitat's Zigbee mesh how-to recommends against bulbs mixed with non-bulb Zigbee devices for this reason. So, jut something to keep in mind as you build your Zigbee mesh if you weren't already aware: if things stop working well, these bulbs are probably why. 
