1366 - Incorrect integer value: '' for column 'customer_id' at row 1

insert into whos_online (customer_id, full_name, session_id, ip_address, time_entry, time_last_click, last_page_url) values ('', 'Guest', 'b4b66d2d2a95b7c8840d9d85e40f42df', '18.206.76.226', '1627557433', '1627557433', '/')

[XT SQL Error]