There are many wasy.
Using URL, Make sure when you upload a URL it start with //link_of_img make sure you use https: before that link when rendering.
So, it will be https://link_of_img .
but you can also upload multiple imgaes using a list on a backend workflow. just have a parameter as file.
if i am missing some thing , i am sorry. but you can always ping me, and we get on video and solve it.
Really want to help. 