Deploying react js app by setting up a reverse proxy

I have a react js app running on localhost:3000 on my vps (godaddy).

I have set up a reverse proxy using Apache web server on /var/www/html/ecommerce/app by setting .htaccess like this:

DirectoryIndex disabled

RewriteEngine On 
RewriteRule ^(.*)$ http://127.0.0.1:3000/$1 [P,L] 
RewriteRule ^$ http://127.0.0.1:3000 [P,L] 

The idea is to access the app via http://my-vps-public-ip/ecommerce/app.

Right now the page fails to load. Any help would be appreciated.

To test if the app is indeed running on http://localhost:3000 I made an SSH tunnel:

ssh -L 3000:$GD_IP:3000 -N logan@$GD_IP

And, when I view it from my end http://localhost:3000, it worked! So something is wrong with my Apache configuration?. I did a similar reverse proxy with port 8000 and it worked.

This one worked in a different case:

DirectoryIndex disabled

RewriteEngine On 
RewriteRule ^(.*)$ http://127.0.0.1:8000/api/$1 [P,L] 
RewriteRule ^$ http://127.0.0.1:8000/api [P,L] 

By 'worked' I mean, say .htaccess file is under /var/www/html/ecommerce/api, then I can access it via http://my-vps-public-ip/ecommerce/api.

When I visited http://$GD_IP:3000 the site opens! But why? .htaccess file is under /var/www/html/ecommerce/app so I was thinking it will be accessible via http://$GD_IP/ecommerce/app?

Output of ss command:

logan@vps:~$ ss -ltn 'sport = :8000'
State     Recv-Q     Send-Q         Local Address:Port         Peer Address:Port    Process    
LISTEN    0          511                        *:8000                    *:* 

logan@vps:~$ ss -ltn 'sport = :3000'
State     Recv-Q     Send-Q         Local Address:Port         Peer Address:Port    Process    
LISTEN    0          511                  0.0.0.0:3000              0.0.0.0:*

Output of apachectl -S:

logan@vps:~$ apachectl -S
AH00558: apache2: Could not reliably determine the server's fully qualified domain name, using ip-184-168-120-55.ip.secureserver.net. Set the 'ServerName' directive globally to suppress this message
VirtualHost configuration:
*:80                   ip-184-168-120-55.ip.secureserver.net (/etc/apache2/sites-enabled/000-default.conf:1)
ServerRoot: "/etc/apache2"
Main DocumentRoot: "/var/www/html"
Main ErrorLog: "/var/log/apache2/error.log"
Mutex proxy: using_defaults
Mutex default: dir="/var/run/apache2/" mechanism=default 
Mutex watchdog-callback: using_defaults
Mutex rewrite-map: using_defaults
PidFile: "/var/run/apache2/apache2.pid"
Define: DUMP_VHOSTS
Define: DUMP_RUN_CFG
User: name="www-data" id=33 not_used
Group: name="www-data" id=33 not_used