Regarding the issue of switching between Bluetooth and IR (infrared) for Google TV sticks (such as Chromecast with Google TV) remote controls, these types of remote controls are usually designed to be connected to the TV stick via Bluetooth by default. Here are some suggestions to help you understand possible switching methods or confirm the current connection method:
Bluetooth connection
Make sure the TV stick is turned on and enter the Bluetooth settings interface.  
Remote pairing: Long press a specific button on the remote control (such as the settings button or pairing button) until the indicator light starts flashing, indicating that the remote control has entered pairing mode.  
TV Stick Search Device: In the Bluetooth settings interface of the TV stick, select 'Search Device' or 'Add New Device', find the name of the remote control and click Connect.  
Complete pairing: Enter the pairing code (usually '0000' or '1234', please refer to the remote control manual for details) according to the prompts. After successful pairing, the remote control indicator light will turn on continuously.  
IR infrared connection
For a TV stick remote control that supports IR infrared, its working principle is to emit an infrared beam, and the TV stick will perform corresponding operations after receiving the signal. Usually, this type of remote control can be used directly without special settings, just make sure that the transmitting end of the remote control is aligned with the receiving end of the TV stick.  
Note: If both the remote control and TV stick support Bluetooth and IR, but there is no clear switch button or setting option on the remote control, it is possible that the remote control has been set to default Bluetooth connection at the factory. At this point, you may not be able to directly switch to IR mode unless both the remote control and TV stick support this switching function and provide corresponding setting options