Sometimes WordPress user, or better yet a premium theme user, will be required to create a temporary account for support purpose. WordPress doesn’t tell you how to create a temporary user, they just create an administrator user when you install WordPress, there is no option to create another one.
Once you create the temporary user and the support (or whatever reason) is done, you simply delete the user and have a good night sleep.
Create a temporary WordPress account
Once you go to Users -> Add New, you’ll have some inputs to fill in.
Kindly note that “Role” as this will effect what the user can and cannot do on your WordPress site. Kindly refer here for role and it capabilities.
TL;DR
Administrator – somebody who has access to all the administration features within a single site.
Editor – somebody who can publish and manage posts including the posts of other users.
Author – somebody who can publish and manage their own posts.
Contributor – somebody who can write and manage their own posts but cannot publish them.
Subscriber – somebody who can only manage their profile.
Delete a user
To delete the user, go to Users -> All Users, hover the username, “Edit” and “Delete” link will appear, simply click on the “Delete” link to remove the user.
You can use following plugin for create a temporary user or disable user.
https://wordpress.org/plugins/temporary-access-for-users/