Secure Plug with Retaining Nut

What happens here

From underneath the sink, locate the threaded shaft of the installed hole plug. Thread the plastic retaining nut onto the shaft and tighten it securely by hand. For final tightening, especially in confined spaces, use a specialized basin wrench (a Ridgid brand wrench is shown) to snugly secure the plug. Do not overtighten, but ensure it's firm enough to prevent movement and maintain the seal.

Goal: Fasten the hole plug securely from underneath the countertop.