Second monitor same resolution as first + GSync?

I would like to connect a second monitor to my computer. My main monitor has WQHD resolution and GSync. Does the second monitor have to have the same resolution + GSync or can I also connect a normal Full HD without GSync? Will GSync still work on the main monitor if the second one doesn't have one? No games should be displayed on the second monitor, only windows such as OBS or the Twitch chat.

Graphics card is a 2070 Super and operating system is Windows 10

The resolution and Gsync compatibility are irrelevant. You could also connect NEN 8k with NEM hd monitor would also work and gsync of course still works on the 1st monitor why should it no longer do that?

Many thanks for your response! I thought the monitors might get in each other's way if one had different properties than the other.