[Beginner] Subdomain Setup to specific IP:port (sneaky configuration)

Hello everyone! I’m looking forward to receiving support and help from the community! Here’s the challenge!

#Beginner:

To kick it off, I am an extreme beginner at this. so, the more detailed/step-by-step answer you can provide the better for me and any other beginner seeking a similar solution.

#Context: There are three variables for the current issue:

• I have a domain name registered in a place
• The root/main domain (naggiar.net) is routed to a hosting server outside Digital OCean
• However, a developer has created a web app (REACT/NodeJS) and we installed it on Digital ocean on the following IP: http://68.183.218.18:5001

#What’s needed:

• I created a subdomain (shop.naggiar.net)which I would like to point to the IP and port (http://68.183.218.18:5001)

#Here is what we’ve done so far:

• Created a subdomain shop.naggiar.net
• Created an A record to point to the IP 68.183.218.18

#How can you help?

• What is/are the next step(s) that we need to do?
• on which server should they need to be done?

Looking forward to your support and help! Thanks,