Go to LinkedIn, Facebook or any other social media profile where you have a nice image of yourself, and then go to your profile. If you dont have any social media account, see if you can find an image of yourself online elsewhere. If there is no photo of you online, upload a photo to an image hosting website, like www.imgur.com
Now, right-click on the photo, and then select 'Open image'. It now shows up on a blank background. The url in the top bar is the url we need! Ideally, it has something like ".jpg", ".png" or ".svg" at the end.
Just copy this address and paste it into the form! If you want to check again if you have the right url, just open the address in a new browser window. If the correct image comes up, you did everything right!