src/Protocol/Http/Request.php
public function withCertificate(string $certificate): Request
    {
        $cloned = clone $this;

        $cloned->certificate = $certificate;

        return $cloned;
    }
public function withCertificate(string $certificate): Request
    {
        $cloned = clone $this;

        $cloned->certificate = $certificate;

        return $cloned;
    }
Use certificate for send request

@param string $certificate

@return Request