Use high gluten (bread) flour for hand pulled noodles
Hand pulled noodles are normally made with low to medium gluten flour (cake flour)

Alkalines, like Lye water or baking soda are added to soften hard flours (high gluten). You use much less for soft flour

Elastic may not be the word you want, supple is what you want in the dough. It need to be able to pull and not break, and stay that way

The dough needs to sit a few hours to fully saturate. Also keep it warm at a high-ish room temperature to keep it supple

It can take years of practice to pull noodles well