Hello There,
Thanks for writing in!
You can manage the Permissions in Pro > Settings > Permissions. To know more about permissions, you can check it here: https://theme.co/apex/forum/t/permissions/32879/1
In most case, you will have to enable the Posts so that your contributor can only access the posts and not the header/footers or any other section that you do not want him to access. Please keep in mind that the Contributors can write, edit, and delete their own unpublished posts, but their content must be reviewed and published by an Admin or Editor. It’s important to note that Contributors can’t access the Media Library, so if they want to use specific images, videos, or audio files in the Media Library, they have to ask for assistance from an Admin or Editor. The Contributor role is a popular option for guest authors who don’t submit content on a regular basis.
Hope this helps.