How to delete or add an entry to the database?

Question

Laravel

Hello!
The database has multiple entries for the same category.
When editing (adding or deleting) keywords, they are displayed in a general list.

How to implement so that when a string (keyword) is deleted from the text field, the corresponding entry in the database is deleted, and when added, it is added?
At the same time, when adding, I would also like to check if the same entry exists in another cell.

Answer 1

Read in the dock - Syncing Associations