After installing, you must trust the EMS Developer Profile.
1️⃣ Try to open the app — you’ll see a trust warning.
2️⃣ Go to Settings → General → VPN & Device Management
3️⃣ Tap “CHEVRA HATZALAH INC”
4️⃣ Tap “Trust”
5️⃣ Return to the Home Screen and launch the app
6️⃣ Allow push notifications so dispatch alerts reach you