We have done a few of these now, installing fire pits in patios or just outside them.  We connect gas from the house which supplys a grate of concentric circles with holes for the gas placed evenly around it.  The valve controlling the rate of gas and fire size is just directly upwards in the picture, under a shiny brass lid set at paver height. We enjoyed placing the rocks around it, providing some of that good old primitive seating around the fire.  It provides warmth on the occasional cool Summer nights we get at 5,000 feet above sea level.  “Smores, anyone?”