Hi @gjohnson7771. The ArduinoBLE library is only for use with the nRF52840-based Arduino boards (Nano 33 BLE) and the Arduino boards that use a u-blox NINA-W102 module (Arduino Nano 33 IoT, MKR WiFi 1010). The library can't be used with your 3rd party board.. You will either need to control the CC2540 directly using AT commands sent over Serial, or else find an Arduino library that supports the C2540.
You can search for a library in the Arduino IDE's Library Manager (Sketch > Include Library > Manage Libraries....