How Can We Annotate in a PDF in the Ibook App of An Ipad Pro?

How can we annotate in a PDF in the iBook app of an iPad Pro?

Both iAnnotate and GoodReader support proper PDF annotations. This means t appear as real annotations (with pop-up notes) when opened in other viewers like Nitro Reader, Nitro Pro and Online Pdf Annotator Reader, and can be replied to, etc. (If your viewer allows it). Whereas some other iPad PDF viewers I've tried treat the PDF pages as images and you wind up with scribbles directly on the page and no way to attach text feedback to them -- t are terrible for collaborating on. I'd give GoodReader a try first. The major difference between the two when annotation/drawing is GoodReader lets you attach text feedback to the drawing markups you add via pop-up notes. That is critical for me when marking up page content.