Why is the script not unachoring the model i made in the workspace?

an Instance of type Model does not have a property called Anchored. Anchored is a property of Parts not models. If you want to unanchor a model you will have to unanchor every single part that is inside recursive loop would do it something like

function Unanchor(parent)
	for _, p in ipairs(parent)do
		if p:IsA("BasePart")then
			p.Anchored = false
		end
		Unanchor(p)
	end
end

Unanchor(game.Workspace.Model1)