I'm developing an integration with an API which requires to whitelist customers based on IP addresses. I can easily get outbound IP from Production environments such as Azure or AWS and get those whitelisted.
How can I configure it for my desktop whose public IP keeps on changing after every few hours?
Getting a fixed IP address for your home computer is dependant on your internet provider. Sometimes they offer fixed IPs for 'Business' customers only or such.
Another solution might be to stand up an OpenVPN instance in your cloud then only whitelist that IP address and your expected partner prod addresses. Then you just connect to your VPN to access your API, you can do this from anywhere as your only dependant on the IP address of the cloud OpenVPN instance.
This solution also scales with your development as you only need to add new OpenVPN users to let other developers work with you and don't need their ever changing IP addresses.