How do you add a domain name onto a XAMPP website that will work on the internet

I'm new to port forwarding and doing web stuff, so sorry if I'm making stupid mistakes

I can connect to my website through a different device with the IP of my server computer, however when I try to use my domain it doesn't connect to the website. However this shows that my portforwarding works, and the website can be viewed on other computers.

Im not really sure what I'm support to do, and all of the tutorials on google just tell me to use this code in the httpd-vhosts.conf file

<VirtualHost *:80>
    DocumentRoot "C:\xampp\htdocs\projects\mywebsite.com"
    ServerName mywebsite.com
    ServerAlias www.mywebsite.com
</VirtualHost>