Search for SJR-BTM525, this is the name of the blue module and find module pinout
To enable USB communication you need to solder "USB_DP" and "USB_DM" to your preferred connector and you must solder/connect "VCHG" to your power voltage, without this the USB is disabled.
I connected "VCHG" to +5V currently working but not sure, maybe you should use +3.3V
PLEASE REFER TO CHIP DATASHEET (not module) TO AVOID ANY DAMAGE!!!
No-one takes responsibility for how you modded this module ;)