Here's a helpful guide on how to legally and safely acquire and use Metasploit Pro:
You can request a legitimate temporary license key by registering on the Rapid7 Metasploit Pro Download page. Rapid7 will send the key to the email address provided. i metasploit pro license key free free free free
Note that the "Community Edition" was retired in 2019, so the Framework is now the primary free path [2]. Here's a helpful guide on how to legally