My Model H801X is not recognized. How do I download a manual update?

I went to tvupdate.roku.com to manually download an update but it does not recognize the model number my TV displays in settings, which is H801X. It is asking for 4 numbers and one letter. Nothing in that pattern is available to me on this device. It's a 32-inch Onn model 100012589 that is not displayed on Roku's website but is available at Walmart still. 

After a week this TV is no longer connecting to the internet. We primarily screen mirror our devices to it, we don't really use it for TV. After attempting all the basic steps, power cycle, reconnect to the network, reset button on the back, full system reset... nothing is working. 

I tried to research both the Roku Model Number as well as the Onn Model Number in hopes that I would find a model number I could use for this TV but no luck. I read here in the community that Walmart models typically have "RW" at the end, but this one doesn't. I assume because Onn is Walmart's brand and there's no need to identify it? I'm at a loss. Any help is appreciated!