SSL Error when using self signed certificate

I'm submitting a...

[x ] Bug report 

[ ] Feature request

## Current behavior
When I'm try to call API from self signed certificate HTTPS server, the webview response error, therefore I can't retrieve the data.
I'm also try this solution, but it didn't work https://stackoverflow.com/questions/46777758/how-to-bypass-ssl-check-in-ios-11-using-ionic-cordova-framework-and-self-signed

## Expected behavior
Could you please guide me how to bypass the ssl error, I need to build app for client testing.

Thank you!