Kaico SEGA Genesis 1080p HDMI Adapter - for use with Sega Megadrive - Supports S Video Output – Supports PAL and NTSC Consoles – Aspect Ratio Switch for 16:9 or 4:3

Get this one: https://www.amazon.com/dp/B08GFHKVB3 Comes with an adapter (which you may or may not need). Better to have this and not need it, than to need it and not have it. If you can afford it, then this cable is one of the best options available now: https://www.retrogamingcables.co.uk/RAD2X-CABLES/SEGA-MEGA-DRIVE-2-GENESIS-2-32X-HD-RAD2X-HDMI-480P-CABLE If that's too expensive, then check out the Retroscaler2X or the Kaico Sega Genesis HDMI Cable. These are budget options, but will hold you over while you save for something better (or maybe work just fine for your needs).