Problems

I have the blog site of http://www.myisiah58.com I have not a clue what version I have but want to add the “Simple Author Box”. I have down loaded it twice and it still does not appear on my site. I deactivated then deleted and tried again. It says “it has not been tested on my version of Word Press>” What does that mean and how do I get around it and get the author box on my site?

https://ww.wp.xz.cn/plugins/simple-author-box/