I tried to look for different solutions on the internet but I found many different ones. So I would like to ask if anyone knows how to make GUIs "responsive" (That is, they adapt to every screen resolution)
Hi! Back then I had the exact same problem as you when game developing. GUIs I made in Roblox Studio would look way differently on other devices. When doing this I suggest using the Emulator feature in studio. You can look at the point of view of other devices.
There are plugins that I'd definitely recommend. The plugin I use is called AutoScale. You can customize your GUIs so that they can look better in other screens. You can convert their size and position by selecting the GUI and clicking on Scale. You can also add GUI constraints so that they can maintain the size on different screens as well.
Click here in case you want the DevForum post.
You can also click here for the actual plugin link.