Backend Developer for Server Configuration

I am looking for an experienced backend/server developer to make a small configuration change to my server.
Current setup:
• The application is hosted on a DigitalOcean droplet
• Web server: Nginx
• Application directory:
/var/www/html/contract-connections
Right now the domain contractconnectionsnz.com points directly to the application landing page (sign in / sign up).
What I want to achieve:
contractconnectionsnz.com should load my new marketing website (hosted separately).
The existing application should still run on the server but be accessible via a subdomain, for example:
app.contractconnectionsnz.com
Users will click a button on the website which will redirect them to the application landing page.
Tasks required:
• SSH into the DigitalOcean server
• Update the Nginx configuration
• Configure the subdomain for the application
• Ensure both the website and application load correctly
• Restart Nginx and confirm everything works
This should be a quick task for someone experienced with Nginx and DigitalOcean.
I will provide:
• Server SSH credentials
• Domain details
• Access if DNS changes are required