src/Publisher.php
private function setAuthorizationHeader(string $accessToken): self
    {
        $this->accessToken = $accessToken;

        $this->options->set(
            'default_headers',
            array_merge(
                $this->options->get('default_headers'),
                [
                    'Authorization' => 'Bearer ' . $accessToken,
                ]
            )
        );

        return $this;
    }
private function setAuthorizationHeader(string $accessToken): self
    {
        $this->accessToken = $accessToken;

        $this->options->set(
            'default_headers',
            array_merge(
                $this->options->get('default_headers'),
                [
                    'Authorization' => 'Bearer ' . $accessToken,
                ]
            )
        );

        return $this;
    }
set header for OAuth 2.0