If you have a legitimate license for v4, you can usually upgrade to the current Soundtoys 5 Go to product viewer dialog for this item.
If you need Soundtoys plugins, use the official website. If you cannot afford them, consider alternatives: soundtoystdmvstrtasauv402osxintelxvxdmg top
If you could provide more context or clarify your specific question, I'd be happy to give a more targeted response. If you have a legitimate license for v4,