Select a project you want to share and click on the users icon on the project card. Click Manage users and a window for managing users for this particular project appears. You can add as many users as you want and assign them different roles.
If the person you want to invite is not an existing SciNote user, invite them to SciNote first by clicking on your avatar in the top right corner of your dashboard and selecting Invite people to SciNote from the dropdown menu.
Type in one or multiple emails of people you want to invite and press ENTER. Finish the action by clicking the Invite user/s button and assigning them a user role.
Don't forget to add the new user to the project as well, after they accept your invitation to SciNote.
An email with instructions on creating a free SciNote account will be sent to them.
To learn more about SciNote user privileges and roles watch this video tutorial.