Yes! BT-S3 helmet Bluetooth can use Siri function but need to key it from your phone.
If your phone has Siri or Google’s assistant, then the BT-S3 motorcycle helmet intercom can use it.
The Inter Phone is a Bluetooth Headset designed for the motorcycle rider and passenger who wish to have clear and reliable wireless communications while riding.
BT-S3 motorcycle helmet Bluetooth headsets are used for 2 riders intercom, If you want to communicate with more riders, you can buy the Fodsports M1-S Pro motorcycle Bluetooth headset from my store, it can pair 8 riders at the same time.

Thanks to the customer’s answer above.
BT-S3 motorcycle headset can only be paired with Fodsports brand intercoms, like Fodsports BT-S2, V6 PLUS, M1S Pro…
BT-S3 motorcycle Bluetooth communication headsets are used for 2 riders intercom, If you want to communicate with more riders, you can buy the Fodsports M1-S Pro Bluetooth motorcycle headset from my store, it can pair 8 riders at the same time.

Press “+” to increase the volume, press “-” to reduce the volume.
About your issue, maybe the both intercom didn’t paired well. Please kindly pair them again:
Long press the Power button of both intercom at the same time, don’t give up until you see the Blue/Red light flashing alternately.
And then short press (one time click) one of the power button. and later the light would become Blue. That means they paired successfully.