A: Hi. Thanks for your question. You can upload books in the reference manager in pdf form with document size limits of 50 MB and upto 1000 pages if they are essentially text based. With youtube links, you can use chatwithpdf feature for chatting with the YT transcript although it currently is not supported in reference manager. (we should be making this feature available in near future)
Web links is supported in the Reference Manager. PPT slides as a format is not supported but you can upload after saving them in pdf form.