How to upload pictures to Facebook from my computer if I have an iPhone that won't let me?

I can send pictures on Facebook though messenger on my phone and upload from my phone, but when I try to upload pictures from my computer to send to friends it won't let me, same goes for when I try to upload a picture on my timeline thing. Can someone help me, this is starting to upset me.

If Your Iphone is Not Letting You Add the Pictures To your Computer Try Uploading the Photos From Your Iphone Instead of the Computer

Hope This Helps