How to get videos taken on my camera transferred to my iphone?

I already put the videos from the sd card onto my computer. Now how can i transfer them over to my iphone? I tried dragging them over in file explorer but it didn't work. Any suggestions?

You can put them into itunes and then plug in your phone and it'll upload into videos

Post them to OneDrive and then get OneDrive app for phone.

Have your iTunes installed. Find the icon on left top corner, press it and go to add file to library. If you just can't add it, it is probably the video format, find if it suits for your iphone and if it not, just find some video converter to make a convert.