Here are a few solutions to use iPhones as cameras in OBS to go live to EventLive platform.

How to Live Stream with EventLive and OBS Studio

Using your phone as a web cam is helpful with OBS streaming to EventLive, and also for your calls on Zoom, Meet, Teams, Skype, Slack, Google Chrome, Cisco Webex, etc. It usually is much better quality than other webcams.

ElGato EpocCam (Recommended)
https://www.elgato.com/en/epoccam
$7.99
Wi-Fi

iVCam
https://www.e2esoft.com/ivcam/
$24.99 lifetime
Windows
Wi-Fi or USB

OBS.camera
https://obs.camera/
$17.99
MacOS, Windows
Wireless (NDI support) or USB

OBS Ninja
https://obs.ninja/
Free
Advanced

Reincubate Camo
https://reincubate.com/camo/
Windows, MacOS
$39.99 / year

NDI Camera app
https://apps.apple.com/us/app/ndi-hx-camera/id1477266080
$19.99

On slow networks it's recommendable to use USB when possible, to avoid affecting the stream quality even more.