Actions may not have an undefined "type" property in reactjs

What is this error saying? I got this error while dispatching request to the redux store.

Error: Actions may not have an undefined "type" property. Have you misspelled a constant?
client/src/redux/alert/alertActions.jsx:18
  15 |             variant: variant
  16 |         }
  17 |     })
> 18 |     setTimeout(()=> dispatch(actionType(REMOVE_ALERT, {id: 1})),timeout)
  19 | }
  20 |