How can I control Arduino Uno Wifi Re2 with bluetooth?

I've been trying to see how I could use an app for bluetooth cars with the Uno Wifi Re2 board. I haven't found any luck with finding the board when scanning regularly. Any ideas?

If your Uno Wifi Rev 2 has a NINA module like the Nano 33 IoT, it supports BLE, not classic Bluetooth.

See this thread.

Do you know if there are any good controllers for android that can work with BLE?

I really do not know anything about BLE.

That said, the serial Bluetooth terminal app that I use for testing my Bluetooth (classic) devices has a Bluetooth LE function. I do not know if it will work with your Uno Wifi Rev 2. Look in the Devices menu.

The previously referenced Kai Morich's Serial Bluetooth Terminal app will indeed communicate with a BLE peripheral using the Nordic_UART Service. Indeed I have used several android BLE terminal apps and they all appear to use that service as a default.

//Nordic uart Service
#define BLE_UART_SERVICE_UUID        "6E400001-B5A3-F393-E0A9-E50E24DCCA9E"
#define BLE_CHARACTERISTIC_UUID_RX   "6E400002-B5A3-F393-E0A9-E50E24DCCA9E"
#define BLE_CHARACTERISTIC_UUID_TX   "6E400003-B5A3-F393-E0A9-E50E24DCCA9E"

If you don't want to write peripheral code using this service, there is a library you can use to set up the UART service on a device running ArduinoBLE.h. The HardwareBLESerial library is available through the library manager.

I have used this library with a Nano33BLE but have no experience with the WiFi Rev2. Does the BLE use ArduinoBLE.h? If so then the library may work.