Hello @Mesut!
I want to scold you a little:
1) Please check the forum section where you creating a new topic. Topics with questions should be in appropriate section 'Questions & Help'. What is the point of forum sections if no one will use their logical purpose? The forum is large enough and for its convenient use you need to somehow categorize the topics;
2) I saw on your screenshot the phrase:
Are you really the developer of this library? I'm not hinting at anything, but I want to remind about the importance of respecting copyright in our community.
Thank you!
Regarding your question:
1) Where did you get these extensions? Is there detailed instructions on how to install them?
2) Probably the installation instructions are at the beginning of the extension file.
3) These files (skills.lua, variable.lua, timer.lua and funcs.lua) may not be extensions as such, but files with auxiliary functions, for example, for some extension.