Oh, it´s ok to collab: they usually post their drawing as a URL on ufile.io, but you have to download it. (It´s free, but it takes a while) after downloading, once on your anim, you click the settings icon on the left, and you click the green ¨up¨ button, choose the collab file, and the image should appear. To save a drawing, you just go to the settings and click the red ¨down¨ button. The drawing should download. To make it appear, click the green ¨up button¨ and click the file. Then, the image should appear. If I said something confusing, Tell me, and I will fix it. Hope that helps! :)

ur welcome :)