How was the Shortughai site connected to the Indus civilization?

The archaeological site of Shortughai, located in the Amu Darya valley of northern Afghanistan, is identified as a small Harappan colony.12

Its connection to the Indus civilization was primarily strategic and economic. The colony was established to provide control over the export trade of lapis lazuli, a highly valued gemstone sourced from the nearby mines of Badakhshan. By maintaining this settlement far outside the central Indus region, the civilization was able to secure and manage the supply chain of this precious resource.12