Hi,
WP Notes Widget does not have this functionality itself, but you can install an additional plugin to achieve this functionality: https://en-ca.ww.wp.xz.cn/plugins/user-role-editor/. You can give author and contributor roles the ‘post’ capabilities. This will allow them to create notes. However, this will have security implications since it will open up lots of other functionality to authors and contributors elsewhere in you WordPress admin. If this is the direction you would like to take, I would recommend learning more about roles and capabilities first https://codex.ww.wp.xz.cn/Roles_and_Capabilities if you are not familiar with them.
Thank you so much for the guidance and suggestions Steve, I’ll certainly look into it. Thank you~