TryBT is an application to communicate with RX23W which is Renesas Electronics 32-bit MCU supporting Bluetooth® Low Energy. You can check Bluetooth Low Energy communication with the firmware preinstalled in "Target Board for RX23W" that is evaluation board mounting RX23W.
For how to use TryBT, please refer to the document below. https://www.renesas.com/document/apn/rx23w-group-smartphone-application-trybt-android