Add custom action into table

Thank akveo team for the works :)
I want to know if I can add new custom action into the action group. By example, now I want to make an Export button to allow to output a CSV file of table.
- Currently, I can add a button outside and interact with the data without connecting with the table but it would be nice if I can place this button just next to add button.
Or a Delete All button to help remove multiple lines

Another concern, could you please add some examples for `confirmCreate` and `confirmSave` in `settings` to follow? I want to handle the validation of the input field.