Uploading file(pdf,doc) from browser using Ionic

I created web app using Ionic framework(So I cannot use cordova plugins). I want to upload single file to server(based on PHP) and I have the upload API link but I am not getting how to upload the file to the server. i have tried different Angular packages but nothing seems to be working.
Can anyone point me to some tutorial or can give some sample code for uploading a file to server with PHP as backend.

Also Cardova plugins wont work in this case, since I am making a web app.