We checked the serial number you provided and we noticed that your device is a Roku 1 (2710X) which uses a simple (IR) remote. IR remotes don't have an option to be paired since it uses invisible infrared (IR) light to transmit button presses a short distance.
For a simple remote to operate reliably, it must be pointed directly at the Roku device and there must be nothing blocking the signal from traveling to the front of that device, where the IR receiver is located.
You can also check out our website to know the remotes compatible with your player.
Re: pairing a new automatic pairing remote to my Roku SE but it wont pair
You can go with simple $14.99 remote, it won't have tv controls. If you want your Roku remote to control the tv as well, get the $19.99 voice remote. The simple remote will work straight out of the box. Where the voice remote will need to be paired to the Roku first, and then programmed for your tv brand second.