Bought and received my ruuvitag two days ago. Remove the protection from the battery. Download the aps, etc…
Putting new battery into the device. Press (R+B) button, red and green light stay in 3 seconds, but never blink after.
Have you tested if Ruuvi Station can see your RuuviTag? Blinking is really quick and pretty dim, it’s possible that you won’t see it at all if there’s sunlight in the room