Cartalyst\Sentinel\Users\EloquentUser::getUserId(): Return value must be of type int, null returned

[tidcp]

Your Environment

• OS and Version: MacOS, Laravel 6
• PHP Version: 8
• Sentinel Version: 3.0.4

Expected behaviour

Activation::completed($user) to return boolean

Actual behaviour

Activation::completed($user) results in error Cartalyst\Sentinel\Users\EloquentUser::getUserId(): Return value must be of type int, null returned

public function getUserId(): int
{
return $this->getKey();
}

Steps to reproduce

Calling Activation::completed() anywhere leads to this error