Can I use ESP RainMaker without Wi-Fi provisioning?

While Wi-Fi provisioning (BLE or SoftAP) is the recommended method, you can hardcode Wi-Fi credentials for testing:

wifi_config_t wifi_config = {
    .sta = {
        .ssid = "YOUR_SSID",
        .password = "YOUR_PASSWORD",
    },
};
esp_wifi_set_config(WIFI_IF_STA, &wifi_config);

Warning: Hardcoding credentials is only suitable for development/testing. For production, always use provisioning.