Infrared remotes do not pair at all. The B5, E5 and E5 SE ship with an IR remote (IR-100 or IR-200). Fit batteries and point it at the front of the box. If it does not respond, it is almost always batteries.
Bluetooth remotes pair through the BuzzTV Smart Remote app on the box:
Paired is not the same as connected. Check Android Settings > Remotes & Accessories and confirm it says connected.
To reset the pairing, hold D-pad Down and 0 together for about 4 seconds until the remote blinks. The remote then falls back to infrared, so it will still work pointed at the box.
Still stuck? Email cs@buzztv.com with a photo of the white label on the underside of your device, which we use for utility and system checks, and tell us what you see on screen. Support is Monday to Friday, 10:00 to 18:00 Eastern.