It is a PDF that you have to download by clicking on the large orange "Download" button on the top of your screen on Mobile or top right of your screen on Desktop.
If you are still unable to open the PDF, there are several tutorials on Pepakura in the Tutorial Index, which has been linked to you multiple times at this point:
Tutorial Index Who can make a Tutorial? A: Anyone How do I make a tutorial? A: Create a thread in any part of the forum you think your tutorial pertains to such as Costume, Props, Soft Parts etc. How do I get the tutorial in the Tutorial Section? A: start a conversation with me or any staff...
www.405th.com
At this point you have created threads asking about all 3 major Build Methods used around here, 3D printing, Foam ,and now Pepakura. Each time you have been given the link to the Tutorial Index, in addition to our members answering your questions as best they can. At some point you really need to take the time to do some research and reading, as it will save you time, money, and resources in the future.