I'm using Deepin 20.9. Sound output is working fine with my "Xiaomi Buds 3T Pro" Bluetooth earphone. But I don't see any "input device" detected. Can i use the microphone of "Xiaomi Buds 3T Pro"?
The kernel needs to be replaced, possibly because the input device is not recognized by the kernel~
Which profile have you selected?
The default A2DP does NOT enable the microphone, obviously.
In order to use the microphone you need HFP - "hands-free" profile - and keep in mind this mode is MONO LO-FI!!