To communicate you need:

• Smartphone (BT) running “meshtastic app”
• ↕ (BT)
• IOT device (BT + LoRa) running “meshtastic firmware”
• ↕ (LoRa)
• IOT device (BT/WIFI+ LoRa) running “meshtastic firmware”
• ↕ (BT)
• Smartphone (BT) running “meshtastic app”

Maps for finding such nodes:

• one maintained by user: https://canvis.app/meshtastic-map
• and an unofficial: https://map.technicallyrural.com/