SMS sending placeholder

Use your provider's HTTP API. Example cURL:

curl -X POST "https://sms.example.com/send" \
  -H "Authorization: Bearer YOUR_KEY" \
  -d '{
    "to":"+995555000000",
    "from":"SmartNet",
    "text":"Technician is on the way"
  }'

Place your SMS configuration in src/config.php -> sms object and call it from PHP where appropriate.