It seems like new GuzzleHttp\Client(ar...ame, $this->password))) of type GuzzleHttp\Client is incompatible with the declared type NotificationChannels\For...xElks\GuzzleHttp\Client of property $client.
Our type inference engine has found an assignment to a property that is incompatible
with the declared type of that property.
Either this assignment is in error or the assigned type should be added
to the documentation/type hint for that property..