Content creation

The really short version:
Suppose I have automatically generated a CoursePresentation with slides that get their content from HTML imported from elsewhere. This HTML may contain links to local files, like documents for download. Assuming I've copied all of those files into the CoursePresentation's content/files/ dir, is there an easy way, like a CSS class I can set, for example, for me to tell H5P to just prepend the appropriate contentUrl to a link's target? For details on why I'm trying to do this, read on...

I try to create "Course presentation" - >Content type "Single choice set" with image.

I receive this message

"Alternative is required and must have some text or at least an image in it."

but I cannot add image for alternative.

Thanks

Hell,

How can I insert "Find the hotspot" in "Course presentation" ?

Thanks