Reverse proxy implemented in Flask is giving 404 errors when accessing Kinsta Wordpress site

Overview:

I would like advice on setting up a reverse proxy so that my Google Cloud Run Python app hosted at example.com proxies content from our Kinsta installation hosted at myblog.kinsta.cloud. For example, example.com/articles/{page} (our main application) should return the same content as myblog.kinsta.com/page

Main Site Setup:

• My app is hosted on a WSGI Gunicorn server.
• The web framework that my app uses is Flask.
• In order to support a reverse proxy, I tried implementing this endpoint:

@app.route('/articles', defaults={'path': ''}, methods=['GET', 'POST'])
@app.route('/articles/<path:path>', methods=['GET', 'POST'])
def articles(path):
    url = f"https://myblog.kinsta.cloud/{path}"  # Construct target URL


    # Forward request headers
    headers = {k: v for k, v in request.headers if k.lower() != 'host'}
    headers['Host'] = 'myblog.kinsta.cloud'  
    headers['X-Forwarded-For'] = request.remote_addr
    headers['X-Real-IP'] = request.remote_addr
    headers['X-Forwarded-Proto'] = request.scheme


    # Make the request
    resp = requests.request(
        method=request.method,
        url=url,
        headers=headers,
        data=request.get_data(),
        cookies=request.cookies,
        allow_redirects=True
    )


    # Filter response headers
    excluded_headers = {'content-encoding', 'content-length', 'transfer-encoding', 'connection'}
    response_headers = {k: v for k, v in resp.headers.items() if k.lower() not in excluded_headers}


    return Response(resp.content, resp.status_code, response_headers)

Subsite Setup:

• My blog is hosted on Kinsta, which automatically gives an initial domain that looks like myblog.kinsta.cloud.
• I asked Kinsta Support to set up the reverse proxy on their end (they have a reverse proxy add-on). They said that in the wp-config file, they added the following code:

$_SERVER['HTTP_HOST'] = 'https://example.com';


/*Include, ONLY if the main site is SSL forced*/
define('FORCE_SSL_ADMIN', true);
if (!empty($_SERVER['HTTP_X_FORWARDED_PROTO']) && strpos($_SERVER['HTTP_X_FORWARDED_PROTO'], 'https') !== false)
               $_SERVER['HTTPS']='on';

• And they also made the following changes in their nginx config.

rewrite ^/articles/(.*)$ /$1 last;

Issue:

Whenever I go to example.com/articles/{page}, the URL changes to example.com/{page} and I see a page not found error.

Question:

Can you please tell me if there's something wrong with how I implemented the reverse proxy in Python?

Thank you!