If you have a YouTube Channel please follow the steps below:
Go to studio.youtube.com.
On the left-hand side, click Settings.
Click Invite and enter the email address of the person you’d like to invite.
Click Access and select Manager and assign firstname.lastname@example.org (you can cut and paste the email from here)
If you would like to see the instructions from YouTube, click here: https://support.google.com/youtube/answer/9481328?hl=en