Using a laptop as a second screen with HDMI

I would like to connect two laptops, where one laptop is the primary and the other serves as a second screen and I would like to do it with wires, ideally HDMI because both computers have that port. Is this possible? Do I need special software? Will I ruin my computer if I try this?

I was inspired by the Windows 10 feature that lets you use a second windows laptop as a second screen wirelessly. I often travel with two laptops (one work, one personal) and having a second screen is really helpful, BUT I usually need it for complex excel spreadsheets and there is so much lag in the wireless functionality, it feels like it takes more time. I decided I'm not opposed to carting around a short HDMI cord if it means I could use both screens without the lag. It's cheaper than purchasing a wireless screen and I'm already carrying both laptops.

Both laptops are Lenovos, both under 6 months old, one is a Ryzen 7 with Radeon RX Vega 10, the other has a Ryzen 5 with a Radeon RX Vega 8. Both running windows 10.  Both have USB-C ports and HDMI ports. Not sure if the specs mean anything.