The link for the latest version of libaacs is at contained within that page. For the sake of clarity, I'll add it here as well:
Link
When you click on this link, you will be able to download a file named '2020-07-26_libaacs_libbdplus.7z' . You do not choose between 32 or 64 bit versions at this stage. Both 32 bit and 64 bit are contained within '2020-07-26_libaacs_libbdplus.7z'
View attachment 67401
After you have downloaded '2020-07-26_libaacs_libbdplus.7z', go to your downloads folder and right click on '2020-07-26_libaacs_libbdplus.7z'. You should have an option provided by 7-zip, WinRAR or another archive tool to extract the files contained in '2020-07-26_libaacs_libbdplus.7z'
View attachment 67402
After you have clicked 'Extract...',