You followed a link on oculus.com that redirects to another website:
https://developer.arm.com/-/media/developer/Graphics%20and%20Multimedia/VR%20Downloads/VR%20on%20Arm%20-%20Developer%20Guide%20Unreal.v2.pdfWe're just checking that you want to follow this link — you can now continue to that website or go back to the home page.