The expression parent::getIdentity(); of type null|string|WebHemi\Data...ity\DataEntityInterface adds the type string to the return on line 67 which is incompatible with the return type declared by the interface WebHemi\Adapter\Auth\Aut...rInterface::getIdentity of type WebHemi\Data\Entity\DataEntityInterface.
The expression 'admin'; of type string adds the type string to the return on line 67 which is incompatible with the return type declared by the interface WebHemi\Adapter\Auth\Aut...rInterface::getIdentity of type WebHemi\Data\Entity\DataEntityInterface.
It seems like the type of the argument is not accepted by the function/method which you are calling.
In some cases, in particular if PHP’s automatic type-juggling kicks in this might be fine. In other cases, however this might be a bug.
We suggest to add an explicit type cast like in the following example: