How do delete API key
If by some reason you need to delete old api key to receive a new one, follow this steps:
Deactivate the plugin
Delete the record from the database
Activate the plugin
After that step, plugin will create a new api key
To delete the record from the database you can run following sql script
DELTE FROM wp_options WHERE name = 'wp_redi_restaurant_options'
or do it with plugin
WP Data Access – App, Table, Form and Chart Builder plugin
Find and open (Explore) table wp_options
Find wp_redi_restaurant_options option and delete it