Use rel="nofollow" for specific links ?

Hello,

according to Google if you don’t your link to be followed we should use “nofollow”
https://support.google.com/webmasters/answer/96569?hl=en

but unfortunately it is not possible with WP Download Manager

could you add this feature?

The thing is, I am getting a lot of errors in Google Webmaster Tools with this links: domain.com/?wpdmact=process&did=

they are usually error 500, even everything is fine with the server, but google spider is trying to follow password protected link and that is the problem

do you have ideas how to fix this?

https://wordpress.org/plugins/download-manager/