Cant pair aeotech multisensor 6

It is not appearing in add devices & I searched how to.reset the device & it says to hit the button but where is the button? Any help is appreciated.

Never mind I figured it out. I had to put the back cover on to reset ir…strange. any tips I should.know foe.this sensor. Other then having a humidity sensor looks like samsung still.has the best motion sensor but I could be wrong.