Check this out https://a.aliexpress.com/_B1YLx0 I didnt brought this but some older version of it, really great connect through bluetooth and it is recharge able through usb.

Seen replica remote on alixpress... Review says they work but connectivity little different than original.

I can't say which one is best since I've only purchased one, but the "MX3" remote worked with my unit well. It has numkeys and an alphabet keyboard which comes in handy for passwords and search, but lacks voice input (be careful if you decide to purchase the mic version, the seller might try to deceive you sending you the non-mic model). It uses a 2.4ghz dongle so you'll need to use the USB port for that. It's air-mouse function works good on both android and PC. Finally, it I were to purchase a new remote, I would try to find something a little more compact since it is full of buttons I end up not using (such as rewind/fast forward) and keep the useful alphabet keyboard.

https://www.youtube.com/watch?v=2GEc8EB0P_0&t=21s

I purchased this android tv Bluetooth mecool airmouse/remote. Took about a month to arrive from China to US https://www.mecoolonline.com/collections/remote/products/mecool-v01-blutooth-voice-control-remote-blutooth-for-mecool-tv-box