Searching for Optitex 11.0.663 usually leads to a rabbit hole of outdated forums and "Setup Key.rar" files that are more likely to contain a virus than a working pattern-making suite.
Since Optitex was acquired by EFI, you can also look into support and licensing via the EFI Optitex Support Portal . Optitex 11 11.0.663 Setup Key.rar
This is a compressed archive. You will need a utility like WinRAR or 7-Zip to extract the contents. Searching for Optitex 11