require '/vendor/autoload.php'; is returning

[mikeyapina]

is returning a failed opening required 'vendor/autoload.php'

I am trying to add a class s3 so I can sign the link being returned from the database in downloadable..

Although I can receive the link signed like I want to when I try to do it programmatically I keep getting an error when I invoke the required vendor/autoload.php AWS is telling me I should use to open the class.

What am I missing here -- a help in direction wold be helpful

Thanks