How to add a user to the forms side for example:
winforms for the purpose of deploying a solution to that particular site.
Foundation 11.x and 12.x
How to give a user access to a site
So in this case best practices is to add the user to the Group which already has access to that particular winform site.
In this case you will find that my Group is called 'Test UG Members' as when I click share while on the 'Winforms site' then show options it will give me the option to share with with 'Test UG Members'
in Screen shot 2.
Screen shot 2 share with 'Test UG Members'
See below on how to add the user to the Group which has access to the Winforms site:
Click on 'Test UG Members' as highlighted:
Click on 'Test UG Members' or what every your group is called: