What are the prerequisites to get the ICCID

[lseg]

Hi,

I would like to know what are the prerequisites to get the ICCID of the sim card:

    int err = 0;

    LOG_INF("Initializing modem library");
    /* initialize the modem library */
    err = nrf_modem_lib_init(NORMAL_MODE);
    if (err)
    {
        LOG_ERR("nrf_modem_lib_init error: %i", err);
    }

    /* register callbacks */
    lte_lc_register_handler(on_modem_lte_lc_event);

    err = nrf_modem_at_printf("AT%%CESQ=1");
    if (err)
    {
        LOG_ERR("nrf_modem_at_printf(CESQ): %i", err);
        return;
    }

    /* initialize info structures, this will contain the SIM card numbers as well */
    err = modem_info_init();
    if (err)
    {
        LOG_ERR("Failed to initialize modem info!");
        return;
    }

    LOG_INF("Changing functional mode");
    modem_get_info(INFO_IMEI); <=== in this internal function I can get the IMEI at this stage

    char temp_char[24] = {0};
    err = nrf_modem_at_cmd(temp_char, sizeof(temp_char), "AT%%XICCID");
    if(err == 0)
    {
        LOG_INF("AT cmd ICCID:    %s", temp_char);
    }
    else
    {
        LOG_ERR("AT cmd ICCID failed %d", err); <=== I always get here with error 65536
    }

This is the code I use, nothing special. I can get the IMEI of the modem but not the ICCID, I always get error 65536 which does not really make sense to me (= 0x10000, which is also not a negative nr).

Question is what do I need more to get the ICCID?
At this moment I do a lte_lc_init_and_connect, but that feels like overkill, just to get the ICCID...

Kind regards