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Using the PL011 UART port
For Raspberry Pi OS and Raspbian Linux, there is a device tree file called disable-bt, which makes the Raspberry Pi disable the Bluetooth module and map pl011 UART on pins 14 and 15.

Step 1 - Login via terminal or desktop and shell

Step 2:  Device Tree settings as below:

Add the device tree to /boot/config.txt to disable the Bluetooth module.

sudo nano /boot/config.txt
Add at the end of the file

dtoverlay=disable-bt
Exit the editor.

Step 3:  You must also disable the hciuart service, which initialises the Bluetooth modem:

sudo systemctl disable hciuart
Step 4:  Reboot your Raspberry Pi to enable the changes:

sudo reboot