Im trying to get an extender but roku website is not accepting my serial number

Eclypse-4-

• If you are able to use your Roku, Settings/System/About will verify, among other things, your Roku model, model number, and serial number.
• You can also find the model and serial number of any devices linked to your Roku account by logging into your account at https://my.roku.com.  Scroll down to your list of linked devices, and click on the Roku of interest
• What model is your Roku?  The free extender offer is only for Roku Streaming Stick products.  Ultra, Express, Premiere, etc are not eligible.
• Also where are you located?  I seem to recall this offer is only for US residents.

There's nothing special about the Roku HDMI extender, it's just a short (4 inches or so) HDMI extension cord with an HDMI plug at one end and an HDMI socket at the other. I use a non-Roku HDMI extension cable several feet long to locate my Streaming Stick+ in an equipment closet on the other side of the wall from my TV. You may be able to find an HDMI extension locally or at a non-Roku online vendor and get one faster than waiting for Roku to process your order and ship it to you. Or use a female-to-female HDMI connector to connect your Roku Stick to a regular (non-extension) HDMI cord.