As of this writing, a link to the textures needed for the second video is posted on the link you provided. For convenience, here’s the url: Box
On the other hand, T_Static_Circle.TGA required by video 4 in the series is not available in the download.
Download the project and you can navigate to all the textures it uses. I just used Windows drag-n-drop to copy the .uasset into my Radial Impact Tutorial Textures folder.