The one I ordered was off of Amazon. The "C2G USB Adapter, Ethernet Adapter with Power, Black, Cables to Go 29749" at this link: https://smile.amazon.com/gp/product/B07B7P2JY5/

It does work. I did notice that if I didn't use the USB power supply that came with the M2000 that the battery was slowly draining down. I had it connected to run my home network recently when we had a failure with our Internet provider. It ran for a about 3 hours and did fine (VoIP phone, a couple media boxes running Hulu and YouTube, and the kid on his tablet playing Roblox). Battery on the M2000 started at 100% and a couple hours later it was at 92%. I had it plugged in to a USB power source, though it wasn't the one that came with the M2000. I haven't checked it precisely, but I think that USB adapter was only a 1amp source, where the adapter for the M2000 is a 2amp or better.I did have to play with the thing for a bit to get it to work because I couldn't remember the connection order. I ended up connecting the c2g network adapter, powering on the M200 and giving that a minute to startup, and then plugging in the USB charger. I had it sitting on a shelf in the basement of my home, maybe a single foot above ground level outside. Had a decent 3 bar signal. I unplugged my network security box from the cable router and connected to the M2000. Logged in to that so I could confirm it had connection and an IP address. Worked fine for those hours. I did disable the WiFI on the M2000 since I already had WiFi setup on the home network. So yes it'll do the job.

You could try something like this https://www.amazon.com/C2G-29479-Ethernet-Adapter-Delivery/dp/B07B7P2JY5. I used it temporarily with my mifi 8000 and it worked pretty well for short periods of time, but my mifi seemed to randomly disconnect if left connected for a long time. This was probably a device issue as opposed to an adapter issue though. Others didn’t seem to have any issues with it, but your mileage might vary.