UniversRadio at the moment does not support in-game PTT binding for the F-14 RIO seat whereas SRS does. SRS, in fact, allows the RIO to assign his pedals as radio PTT directly in DCS and they will immediately work.
I asked Tacno about having a similar feature and he is still work in progress. Meanwhile, if you have a CH Pro Pedals and want to do the same thing, here is the script:
I haven’t coded a CH script in the last 4 or 5 years so there might be a better way to implement it but hey, it works so I’m happy about it.
This script simply monitors the reading on the Left Pedal (by default, it can be changed) and if the reading is greater than 150 (keep in mind that the range on older devices is usually 0→0xFF) it turns on a button in the CMS. When the pedal is released, the CMS button is turned off. That button is the Teamspeak PTT key.
Using the same principle, multiple PTTs can be created.