Hi,
APRS-IS beaconing is available with the Extra Features subscription. To
enable APRS-IS beaconing, go to the Beacon tab, enable "Beacon via
APRS-IS".
It's the third switch from the top of the Beacon tab.
Note that the APRS-IS is a public network, and your position will be
visible to anyone. There is no privacy. Data sent to the APRS-IS is
archived by a number of services, and will be available for download or
viewing even after you stop transmitting.
https://ios-guide.aprs.fi/#_beaconing_via_aprs_is
- Hessu