eos m6 mkii - no wireless flash control

azcii wrote:

... I just bought a 430EX III-RT for my M6 Mark II and I realized I can't use it wirelessly with my camera??

You can. You just have to buy additional gear.

No Canon camera has a built in radio RT transmitter to control flashes remotely over radio. Some Canon cameras (mostly dSLRs) have the ability to use Canon's "smart" optical system to remotely control/fire flashes with a built-in/pop-up flash. In the EOS M lineup, that's apparently reserved for the M5 and M50 lines.

And Canon speedlights don't have dumb S1/S2 optical slave modes that will fire the flash remotely from any flash burst. [But, you'd have no setting remote control, TTL, or HSS. Just the ability to fire the flash off-camera.]

... Is there something similar I can buy for my M6 that will work to trigger my flash wirelessly?

You'd need to have a radio RT flash transmitter on the camera's hotshoe to fire the 430EX III-RT off-camera over radio. A Canon SS-E3-RT, another 430EX III-RT, 600EX-RT or 600EX II-RT, or some third-party alternative (Yongnuo YN-E3-RT, Phottix Laso, Jinbei TR-Q7, etc.)

But if that's too expensive, you could try using Canon's "smart" optical system which is older, with the older gear (580EX, 580EX II, ST-E2, or 3rd party alternative that can be an optical master unit. etc.)

But most of us? We just don't go with Canon OEM flashes and use Godox's system instead. While a TT685-C is not as nice on TTL accuracy/consistency or head rotation or AF assist as a Canon EX speedlight, it can do roughly 90% of everything a 600EX-RT can do, and a bunch of stuff the 600EX-RT cannot (like dumb S1/S2 modes). And it's $110. And an Xpro-C or Flashpoint R2 Pro II-C transmitter to use it off-camera costs $70. A the smaller TT350-C ($85) isn't as nice as an EL-100 for on-camera bounce flash, but it has a built-in radio transceiver and can be part of an off-camera flash system in a way the EL-100 cannot.

So, +1 on seeing if you can return the 430EX III-RT and taking a look at Godox's gear instead.