Dashcam wiring into fuse box

[gl5514]

Hi All,

Have set-up a dashcam and want to wire it into the fuse box, the issue being that I can't work out where / how to attach the earth cable.

Any guidance much appreciated.

[neil-g8km6]

https://flic.kr/p/2oisUYY
The small 10mm nut is where I earned mine.