Expert needed to Integrate 4-Port GSM Gateway with Asterisk/FreePBX for Automated IVR & SMS API

Project Title:
​Expert needed to Integrate 4-Port GSM Gateway with Asterisk/FreePBX for Automated IVR & SMS API
​Project Description:
​"I am looking for a VoIP/Telephony expert to set up a complete automated IVR calling system for my fintech app.
​Hardware & Infrastructure:
​I have a 4-Port GSM Gateway (Dinstar/GoIP or equivalent).
​I have my own Cloud Server (VPS).
​Scope of Work:
​Asterisk/FreePBX Setup: Install and configure Asterisk or FreePBX on my cloud server.
​SIP Trunking: Securely connect my 4-Port GSM Gateway (located at my office) to the Cloud Server via SIP Trunk.
​Automated Calling API: Create an API that my mobile app can trigger to make automated outbound calls (Voice IVR).
​SMS Integration: Enable the ability to send OTPs and automated text messages via the Gateway's SIM cards.
​Call Status & DTMF: The system must report back whether the call was answered and capture any key-press (DTMF) feedback from the user.
​Requirements:
​Previous experience with Asterisk/FreePBX is a must.
​Understanding of SIP, VoIP security, and API integration.
​Knowledge of GSM Gateways and remote configuration."