How to send() rawbody or binary or custom response

[ewwink]

I want to send custom response using

Workerman\Protocols\Http\Response

$response = new Response(200, [
    'Content-Type'     => 'application/json',
    'Content-Encoding' => 'zstd'
], $compressedData); 

$connection->send($response);

but I get error

TypeError: Adapterman\Http::encode(): Argument #1 ($content) must be of type string, Workerman\Protocols\Http\Response given, 
called in /root/www/vendor/workerman/workerman/src/Connection/TcpConnection.php on line 463 and defined in /root/www/vendor/joanhey/adapterman/src/Http.php:469

If I write $connection->send($compressedData);, the browser can't handle it and displays strange characters because the browser considers it as plain text. How do I set the correct header?