Expert 3CX Technician for Business Phone Setup Free edition

We are looking for an experienced 3CX technician to set up and configure a small business phone system. The system is already partially configured but requires a clean setup and proper routing.

Current Setup
Platform: 3CX (Cloud, v20)
SIP Provider: Intertelecom
Existing PBX (Intertelecom) may still be active
Mobile usage via 3CX app
Requirements
1. SIP Trunk Configuration
Proper setup of SIP trunk with Intertelecom
Resolve registration conflicts (single registration issue)
Ensure stable inbound & outbound calling
2. Users / Extensions
Create 4 extensions/users
Configure mobile apps (3CX client)
Set up voicemail for each user (or central voicemail)
3. Call Routing
Outbound rules (basic + prefix handling if needed)
Inbound routing:
Ring Group (all users)
Optional DID-based routing (if applicable)
4. Digital Receptionist (IVR)
Simple IVR menu:
Greeting message
Options (e.g. Press 1, 2, etc.)
Fallback routing
5. Office Hours & Out-of-Hours
Configure working hours
Set up:
Business hours routing
Out-of-office message
6. Optional (Nice to Have)
Separation of calls (e.g. “Athens / Chalkida”) via routing
Basic call flow optimization
Advice on best practices