How to extend Sing-in & Sign-up body with custom fields?

  await signUp.email({
        email: values.email,
        password: values.password,
        name: `${values.firstName} ${values.lastName}`,
        image: image ? await convertImageToBase64(image) : "",
        callbackURL: "/new",
customField: custom_value <-------- // CAN I PASS A CUSTOM VALUE HERE?
        fetchOptions: {}
})

  await signUp.email({
        email: values.email,
        password: values.password,
        name: `${values.firstName} ${values.lastName}`,
        image: image ? await convertImageToBase64(image) : "",
        callbackURL: "/new",
customField: custom_value <-------- // CAN I PASS A CUSTOM VALUE HERE?
        fetchOptions: {}
})