Socket.io via Apache Reverse Proxy

vhost.txt

<VirtualHost *:80>
        ServerName example.com
        ServerAlias example.com www.example.com
        ServerAdmin admin@example.com

        RewriteEngine on
        ReWriteCond %{SERVER_PORT} !^443$
        RewriteRule ^/(.*) https://example.com/$1 [NC,R,L]
</VirtualHost>

<VirtualHost *:443>
        ServerName example.com
        ServerAlias example.com www.example.com
        ServerAdmin admin@example.com

        RewriteEngine On
        RewriteCond %{REQUEST_URI}  ^/socket.io            [NC]
        RewriteCond %{QUERY_STRING} transport=websocket    [NC]
        RewriteRule /(.*)           ws://127.0.0.1:3020/$1 [P,L]

        ProxyPass        /socket.io  http://127.0.0.1:3020/socket.io
        ProxyPassReverse /socket.io  http://127.0.0.1:3020/socket.io

        <Location />
                ProxyPass http://127.0.0.1:3000/
                ProxyPassReverse http://127.0.0.1:3000/
        </Location>

        SSLEngine on
        SSLCertificateFile /etc/letsencrypt/example.com/cert.pem
        SSLCertificateKeyFile /etc/letsencrypt/example.com/privkey.pem
        SSLCertificateChainFile /etc/letsencrypt/example.com/fullchain.pem

        ErrorLog /var/log/apache2/error.log
        CustomLog /var/log/apache2/access.log combined
</VirtualHost>