Image link are the link when you tap on those instead of loading a website a image is load. These links may ends with .jpg or .png or even .gif. So these are the image links. When you use this bot some times there is a requirement to give a image link to the bot. I'll show you couple of way to get links for your own library images. If you already have the link you can skip though. To get an already existing image's link from any website (eg Google Image Search) right click on the image and then copy the image address.
Few ways you can get the links for your images those are the followings:
imgur
then use the linkImgur is a free image hosting service. You can upload your image to imgur
and get the link for your image. Visit https://www.imgur.com then sign in and upload the image. Then follow these steps:
Copy the BBCode Forum link. It'll look something like this:
[img]<https://i.imgur.com/bIzxWzN.png[/img]>
Notice now you have a .png link on your hand. So cutout the rest and take that .png part https://i.imgur.com/bIzxWzN.png. This is your Image url.