fatal: 'ssrf' does not appear to be a git repository

I have already installed everything in my vmware it works but in virtualbox doesnt why? and I need it for virtualbox please help.

echo http://testphp.vulnweb.com/search.php\?test\=query | gf ssrf
fatal: 'ssrf' does not appear to be a git repository
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.
