Whenever you want to create a Pull Request (let's say this is either by a recent change. But, you can also do this with an older change too!), you can go ahead and let GitHub do a lot of the heavy lifting for you and hit the green Compare & Pull Request button (NOT TO BE CONFUSED WITH CLONE OR DOWNLOAD) within the alert box that mentions that you just pushed within a branch.
It will then direct you to a new screen. (Mine is slightly different just because I already have one open.) You will see below this image that it will ask you to Create Pull Request. You just want to be sure that you have the right branch you want to merge into. BASE means which one do we want change and compare is what are we going to put it to! So in this case,
master is behind
example-branch and we want
master to be caught up.