Fix Broken iFrame Chat App on WordPress (React + FastAPI | Post-Migration)

Fix Broken iFrame Chat App on WordPress (React + FastAPI | Post-Migration)

Fiverr Gig Description
We recently migrated our WordPress site (Healsend.com), and our embedded chat app iframe has since stopped working.

Tech Overview
Frontend: React (served as static files via FastAPI)

Backend: FastAPI (running on port 8000)

App URL: https://healsend.com/chat-app

Integration: iFrame embedded in WordPress pages

Current Issue
The iframe now displays a blank or broken page on:

"No message" page

"No visits" page

Internal chat dashboard

This happened after site migration (previously hosted on AWS, now on Liquid Web).

What You’ll Do
Diagnose why iframe is failing (port routing, CORS, iframe restrictions, or file serving errors)

Check FastAPI and NGINX logs

Verify React static files are correctly served under /chat-app

Fix iframe so it loads across all WordPress pages

BONUS: Recommend a better long-term solution than iframe if needed
Only apply if you're experienced with:

WordPress + iframe integrations

React static deployment

FastAPI backend routing

NGINX reverse proxy or equivalent