src/Firebase.php
public function delete($endpoint, $query = [])
    {
        $endpoint = $this->buildUri($endpoint, $query);
        $headers = $this->buildHeaders();

        $this->response = $this->client->delete($endpoint, $headers);

        return $this->response;
    }
public function delete($endpoint, $query = [])
    {
        $endpoint = $this->buildUri($endpoint, $query);
        $headers = $this->buildHeaders();

        $this->response = $this->client->delete($endpoint, $headers);

        return $this->response;
    }
DELETE request.

@param string $endpoint The sub endpoint
@param array  $query    Query parameters

@return object