Forbidden 403

Hello Good Day
i need your Help!!!
i have a codeigniter backend, when i post url it returns forbidden 403 on my ios devices
but in android it works fine
i dont know what to do i also added App Transport Security
im Noob
in ionic 1 pleaseee help

go through following links

Hello Sir thanks for the response
but im new in ionic 1 im using codeigniter for my backend
actually the problem is on my ios on android device is working fine
i also add App Transposrt Security at xcode but no luck.