Create endpoint

    as::io_context ioc;

    // To get IP address from hostname
    as::ip::tcp::socket resolve_sock{ioc};
    as::ip::tcp::resolver res{resolve_sock.get_executor()};

    //                     endpoint is client  choose underlying layer
    auto amep = am::endpoint<am::role::client, am::protocol::mqtt>::create(
        am::protocol_version::v3_1_1, // choose MQTT version v3_1_1 or v5
        ioc.get_executor() // args for underlying layer (mqtt)
        // mqtt is as::basic_stream_socket<as::ip::tcp, as::io_context::executor_type>
    );

    as::io_context ioc;

    // To get IP address from hostname
    as::ip::tcp::socket resolve_sock{ioc};
    as::ip::tcp::resolver res{resolve_sock.get_executor()};

    am::tls::context ctx{am::tls::context::tlsv12};
    ctx.set_verify_mode(am::tls::verify_none);
    // If you want to check server certificate, set cacert as follows.
    // ctx.load_verify_file(cacert);

    auto amep = am::endpoint<am::role::client, am::protocol::mqtts>::create(
        am::protocol_version::v5, // choose MQTT version v3_1_1 or v5
        ioc.get_executor(),  // args for underlying layer (as::ssl::stream<mqtt>)
        ctx
    );

    as::io_context ioc;

    // To get IP address from hostname
    as::ip::tcp::socket resolve_sock{ioc};
    as::ip::tcp::resolver res{resolve_sock.get_executor()};

    auto amep = am::endpoint<am::role::client, am::protocol::ws>::create(
        am::protocol_version::v3_1_1, // choose MQTT version v3_1_1 or v5
        ioc.get_executor()  // args for underlying layer (bs::websocket::stream<mqtt>)
    );

    as::io_context ioc;

    // To get IP address from hostname
    as::ip::tcp::socket resolve_sock{ioc};
    as::ip::tcp::resolver res{resolve_sock.get_executor()};

    am::tls::context ctx{am::tls::context::tlsv12};
    ctx.set_verify_mode(am::tls::verify_none);
    // If you want to check server certificate, set cacert as follows.
    // ctx.load_verify_file(cacert);

    auto amep = am::endpoint<am::role::client, am::protocol::wss>::create(
        am::protocol_version::v3_1_1, // choose MQTT version v3_1_1 or v5
        ioc.get_executor(),  // args for underlying layer ( bs::websocket::stream<mqtts>)
        ctx                  // mqtts is as::ssl::stream<mqtt>
    );