Need help for "This entity does not have a unique ID"

Ill appreciate very much some guide or help creating a unique ID through MQTT or YAML
I’ve looked for instruction, but couldn’t find anything I can understand
I’m trying to make one for my media player Bluesound (=media_player.bluesound_ww)
another one for motion sensor with app IPwebcam (=switch.working_ip_motion_detection)
and one for current temperature from ac connected to HA with ST
again I’ll be great full for good instruction as I am really confused

Mostly you can’t, you can only do that if the integration supports it.

Bluesound doesn’t, and MQTT only does if you’re using MQTT Discovery.

I’m ready to use MQTT Discovery but I don’t know how

The docs cover it, you just have to publish the appropriate MQTT payloads.

thanks way above my level