Choose highlight, underline, strikeout or comment, set the page and the position and size as fractions of the page, and KukPDF draws it onto the page. An optional note of up to 80 characters is written above it.
Your file is processed in your browser and is not uploaded to a Kuklabs server. The page does contact Kuklabs to check your plan, without sending the file.
Each run adds one annotation to one page. Run the tool again on the result to add more.
No. The shapes and text are drawn into the page content, so they cannot be edited as annotations later.
As fractions from 0 to 1 of the page width and height, with y measured from the top.