is it possible to implement the function of displaying who casted buff/debuff?

In core/shared.lua, add a new IDTip.kinds line:

IDTip.kinds = {
	...
	caster = "Caster",
	...
}

Then in clients/shared.lua, change the "SetUnitAura" hooksecurefunc to:

hooksecurefunc(GameTooltip, "SetUnitAura", function(self, ...)
	local id = select(10, UnitAura(...))
	IDTip:addLine(self, id, IDTip.kinds.spell)

	-- add caster name in tooltip
	local caster = select(7, UnitBuff(...))

	-- but if caster name is "player" (ourself), don't bother including it.
	if caster and caster ~= 'player' then
		local name = select(1, UnitName(caster))
		if name then
			IDTip:addLine(self, name, IDTip.kinds.caster);
		end
	end

end)

works with buffs, but does not display the name of the caster on debuffs on dummy for example.
and also in a duel on debuffs applied by me it writes the name of the target, not mine, as well on debuffs on me do not write the name of the player who applied it
mine debuffs

my debuff on enemy

debuffs on dummy

without addons but with idtip doesn't work at all

thanks for the help, I would like to get this to work fully ._.

Should be included in idTip itself in the next release with nameplate aura support also.

Should be included in idTip itself in the next release with nameplate aura support also.

Thanks for the answer!
I tested the update and it doesn't work the way I meant in my request.
For example:
instead of the name of the npc I get "nameplateNumber" and instead of my name on my buff I get "player"

Or do you mean not the current new update, but the next one?