Metasploit Error

Hello,
when i try to use metasploit like youtube video i get a message ( Unable to find a spec satisfying metasploit-framework ) and then after i reinstall ruby i get this message ( ERROR: While executing gem … (Gem::FilePermissionError) You don’t have write permissions for the /var/lib/gems/2.7.0 directory. ) so please i need help

Hello, please read the guidelines before posting.

As for your question, what distribution are you using?

i’m using kali linux virtual box