2nd way would be by tieing into existing gas line inside and running the 1/2 out thru the siding thru a mounting block in the siding to a shut off.
Doing it this way I would put a shut off on the inside also.
Top photo below is same view as above but with a siding mounting block installed, a short nipple of 1/2 and the outside shutoff.
The bottom picture below is a view in the basement looking outside thru the rim joist
See photos below.