If you want a separate form for adding categories, you can use this code to create them. If you want to keep the category creation inside the same form that creates posts, this custom code is not needed. Use a "Tags" field instead, and map it to your category in the "create posts" settings tab.

This example below will add the WordPress Media button to all Rich Text fields used throughout your site. Please note that the Add Media button will only appear for users who have permission to edit WordPress posts.

This code can be used to allow filtering of a View with a Dynamic field that contains UserIDs. This custom filter will make sure the User ID in the Dynamic field is equal to the current user. This code will only be used if you have added a filter to your View that says "Dynamic field is equal to custom".