You will need to expose the computer to the Internet before someone will be able to access a link you share. This can be done a few ways, but I’ll focus on two only.
Method 1 - Network Address Translation, or NAT
This method is a means of allowing traffic destined to your external address through your firewall and accessing an internal resource.
Let’s assume your server has an internal IP Address of 192.168.1.25. You’ll need to go into your gateway’s settings (consult the gateway manufacturer’s documentation on how to do this, look for NAT, Network Address Translation, or some simply call it port forwarding.) and point port 8000 to 192.168.1.25. Once done, you would provide your external IP Address to your client. If you don’t know what your external IP Address is, there are many websites that you can find this out on. One such site is https://whatismyip.com
Let’s say your IP Address is 220.127.116.11.
You’ll then give your client a URL of http://18.104.22.168:8000/public/task/a0c6be26-9595-45a9-81c5-2115c24bbb2f/map/
Method 2 is called DMZ, from the military term, “Demilitarized Zone”
This method involves setting up a special segment on your network that allows external access to the addresses listed within the DMZ settings. Once again, you’ll need to consult the documentation for your gateway as there are hundreds to thousands of products out there, I can’t possibly begin to guess what you’re using.
I recommend that you use NAT, if possible.
If you’re using a native install, this will be much easier. My experience with Docker is very limited, and perhaps someone can chime in here with info about how to get the IP Address of the Docker instance.
Also, if you’re asking these kinds of questions, you likely have a dynamic IP Address from your ISP. That means that your IP Address can change. Depending upon the ISP, it could stay the same for a day, a week, or until you reboot your gateway/router. You may want to look at a dynamic DNS service if you will be doing this sort of thing often. I’ve used Dynamic DNS or https://dyn.com for many years, long before they went commercial. They have a free offering that will allow you to have a subdomain off of many domains they have to pick from. You could get something like “odm.mylinuxbox.com”, or similar. You can also elect to pay for the service and be able to tie it to your own domain name. Once again, this is just one of may services like it now.