I bought a card for my Apple //e that allows the Apple to send video to an HDMI monitor. It's called the A2DVI, and I got it here:
https://jcm-1.com/product/a2dvi-apple-ii-digital-video-adapter/
It does exactly what it says. I had Choplifter! on an OLED screen within minutes, although I suspect there has to be a way to get it into 4:3 mode that I haven't found yet.

A2DVI v2.0 - Apple II Digital Video Adapter - Joe's Computer Museum
Get ready for the best video the Apple ][ has ever seen. The A2DVI produces a digital video stream from your Apple II's memory. The signal is output via an HDMI-compatible connector, giving your Apple II the option of output to modern displays. No more analog signal conversion required.