Impossible to apply this theme?

Hello, I'm new to Linux and I'm using Mint 22.1 Cinnamon, I've tried to apply this theme: https://github.com/L4ki/Magna-Plasma-Themes and other themes from this author and I just cannot do it, I do not know why or if they are only for other distros. What I do is I extract the folder that says GTK theme to the ~/.themes/ it appears in the applications section of the Themes app but not in the Desktop, and even if I only apply the applications one it doesn't look anything like the pictures. Can someone help me?

Thanks!