mysql – Attempts to load data with a foreign status key into a table and does not accept null

I have a name and an address CSZ table with a foreign key from the field state in the state table. I use mysql v8 and use the import wizard for mysql workbenches to do the import. When I load a record with a valid status, it works fine. If I leave the status blank, the following error message appears: "The line import failed with the following error: (" Incorrect integer value: & # 39; for column & # 39; StateId & # 39; in line 1 ", 1366) ". I have an integer stateID and the field is also an integer and I load the integer value for that state. My question is why it does not accept a null value?