@Anshmodi said:
API not loading using cellular network
API URL does not loading when connected o cellular network
every time it is connected to a cellular network
but if VPN connects to that same cellular then the API works properly
otherwise it works with wifi

I had a hard time figuring out where it works and where it doesn't.
It seems that:

1. It works on your home or office Wi-Fi network.
2. It works on your cellular network using a VPN.
3. But it doesn't work on your cellular network without a VPN.

It's probably a DNS blocking issue.
What country are you in?
What is your cellular service?
What is your ISP - internet service provider?

Check if the DNS for the 3 methods above is the same.
I think your cellular DNS is different.
Try changing it to 8.8.8.8 Google.

Let us know the result here.