These can only be set by a Space Admin
Within a space, the space admin can configure which users can create or edit approvals in Confluence. This gives you more control over the use of Approvals for Confluence across pages and spaces. To do this:
Access Space Settings and then navigate to Content Tools > Approvals
Under Permissions, click on groups and enter the group(s) you would like to give the permission to create and edit approvals.
Once complete, only users belonging to those groups have the ability to add or update page approvals.