How to set submit as disabled until form completed?

<form.Subscribe
        selector={(state) => [state.canSubmit, state.isSubmitting, state.isPristine]}
        children={([canSubmit, isSubmitting, isPristine]) => (
            <Button
              fullWidth
              disabled={isPristine || !canSubmit}
              color="green"
              type="submit"
              leftSection={<Icon icon="save" type="far" />}
              loading={isSubmitting as boolean}
            >
            Login
          </Button>
        )}
      />