First of all check whether nginx is present on the server if not then run the commands to install the nginx:

  sudo apt update

  sudo apt install nginx -y 
  

Now enable and start the nginx service:

  sudo systemctl enable nginx.service
    
  sudo systemctl start nginx.service

So now nginx has installed on the server go to this path /etc/nginx/sites-available and create a file using nano with any name for example rpc and add the below content to point the port 26657 to 80.

  server {

    server_name rpc.test.witval.com;
    #rpc.test.witval.com is domain name
        

    location / {
        proxy_pass http://backend_rpc;
        proxy_set_header Host $host; # Add this line to preserve the original host header
    }

    # Add a separate location block to handle URL rewrite without port
    location ~ ^/(.*)$ {
        proxy_pass http://backend_rpc/$1;
        proxy_set_header Host $host; # Add this line to preserve the original host header
       }
    }

    upstream backend_rpc {
    server rpc.test.witval.com:26657;
    }

Save the file and create a symbolic link and restart nginx service:

  sudo ln -s /etc/nginx/sites-available/rpc /etc/nginx/sites-enabled
   
  sudo systemctl restart nginx.service
   

After this we have to setup TLS on the domain for that run the following commands:

  sudo apt install certbot python3-certbot-nginx
 
  sudo certbot --nginx -d rpc.test.witval.com
   #-d is for doamin
    

After TLS setuped just restart the nginx service:

  sudo systemctl restart nginx.service

Now we have to do the same for pointing the second domain. So again go to this path /etc/nginx/sites-available and create a file using nano with any name for example api and add the below content to point the port 1317 to 80.

  server {

      server_name api.test.witval.com;

      location / {
                proxy_pass http://localhost:1317/;
        }

   }

Save the file and create a symbolic link and restart nginx service:

  sudo ln -s /etc/nginx/sites-available/api /etc/nginx/sites-enabled
   
  sudo systemctl restart nginx.service

Setup the TLS on the second domain so for that run the below command:

  sudo certbot --nginx -d api.test.witval.com

So after above all the steps just restart the nginx service and we are done!