The image URL isn’t quite right. I highly recommend you copy/paste these things from the instructions if possible in order to avoid errors like this. Otherwise, go through it character by character until you find the difference (it shouldn’t take long, it’s near the beginning).
Also, it appears that the tests require you have quotes around the URL. Technically, you don’t need them since there are no spaces in the value. But in the real world, they are almost always used, so you should make it a habit now.