Also, if your dryer were electric, the vast majority of full size residential dryers in the US are 240 volt machines and require a dedicated 240 volt, 30 amp NEMA 10-30 or 14-30 outlet on its own circuit, which has a socket face on it about the size of a baseball and is pretty tough to miss. If you don’t have one of those in your laundry area, you ain’t installing an electric dryer regardless.
It almost certainly is a gas line.
Also, if your dryer were electric, the vast majority of full size residential dryers in the US are 240 volt machines and require a dedicated 240 volt, 30 amp NEMA 10-30 or 14-30 outlet on its own circuit, which has a socket face on it about the size of a baseball and is pretty tough to miss. If you don’t have one of those in your laundry area, you ain’t installing an electric dryer regardless.