Are you sure the assignment to $result is correct as parent::updateApiURL() (which targets FlexiPeeHP\FlexiBeeRO::updateApiURL()) seems to always return null.
This check looks for function or method calls that always return null and whose
return value is assigned to a variable.
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: