Both on my cell phone and on my laptop (with Windows 10, if that is important) the respective Instagram app. Since I find dark mode much more pleasant, I switched it to the Instagram app on my mobile phone.
Now I wanted to set the dark mode on the app on my laptop, but I didn't find it. So I wanted to ask if there's this function on the app for the laptop or PC and if so, where I can find the dark mode!
As far as I know, the Instagram app on the desktop is not possible, but you can change Instagram in Chrome to dark mode using an addon.
Here is a 50 second tutorial.