deskthority

Maybe you guys could help me with this.
I'm trying to add a macro in VIA or QMK for £ symbol.

I do not know how to use QMK at all. Tried to achieve this in VIA but also no luck.

There must be a way to program ANSI keyboard to have special characters like £ or other symbols people need.
Does anyone know how to do it?

using ANSI Intl will make your life 200% easier as a European using an ANSI layout

You can look into unicode support for QMK.
https://docs.qmk.fm/#/feature_unicode

If you are on ANSI, as Myoth says, using an International layout in the OS will help. Alternatively, just stick with your usual logical layout and the keyboard will still output most things as usual, regardless of the key legends. For example, there is a workaround built into UK layout for the lack of an extra ISO key: the key that is marked \| on ANSI outputs the scancode for #~, but it changes to \| if you hold Alt Gr (RAlt). And yeah, you'll get £ even though it obviously isn't marked on the key.