As we have checked the account details using the email address you are logged into the forums, you have subscription for Adobe PDF Pack. Are you using Adobe Reader to view pdf files? If yes, you can go to Tools > Comment for drawing markup tools
If not, you can download Reader from this link: Adobe - Adobe Acrobat Reader DC Distribution . Once downloaded, go to Tools > Comment. For more info, visit this link: Use annotation and drawing markup tools to add comments in PDFs, Adobe Acrobat and Acrobat Reader
Let us know if you need any help.