Need help in propagate context with exporter

[HeenaBansal20]

I have three php services running on different ports.
service1 service2 and service3 .
When I do curl to service1 , I can see that trace context is propagating from service1 to service3.
Service 1 received response from Service 2: Service 2 received response from Service 3: Hello from Service 3!

However when I am using exporter , I don't see it happening. Do I need to propagate context manually when using exporters?

<?php
    $traceprovider = \OpenTelemetry\API\Globals::tracerProvider();
    $tracer = $tracerProvider->getTracer('test');
    $root = $tracer->spanBuilder('root')->startSpan();
    $scope = $root->activate();

    $address = "localhost:8004/service1.php";
    $ch = curl_init();
    $url = "http://$address";
    curl_setopt($ch, CURLOPT_URL, $url);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    curl_exec($ch);
    curl_close($ch);
    $root->end();
    $scope->detach();
    $tracerProvider->shutdown();
?>