How to get hidden frames?

[Lybrial]

I want to manipulate a hidden frame from BigWigs - the BigWigsAnchor.
Here is the code on their github:

BigWigs/Bars.lua

As you can see there at the end they do display:Hide(). I guess this is the
reason why I cannot get the frame:

local count = GetNumAddOns();
	
for i = 1, count do
	local name = GetAddOnInfo(i);
	
	if (IsAddOnLoaded(i) and (name == "BigWigs")) then
		-- BigWigs is loaded
                local frame = _G["BigWigsAnchor"];

                if (frame) then
                    -- do stuff
                else
                    print("BigWigsAnchor does not exist");
                end
	end
end

Is there a way to also get and manipulate hidden frames? Or could there be another reason why BigWigsAnchor is always nil?