This is a package you would install through pacman using the -U flag, I’m not sure why you’re copying the contents to the opt/usr directories.
pacman
-U
We’ve gone ahead and updated the installation guide to convey this information more clearly.
Aha! I'm new to pacman and did the mistake of extracting the tar.gz archive. Didn't know you could directly install it using pacman. Thanks for updating the installation guide!