Okla. Stat. tit. 52, § 420.14

The State Liquefied Petroleum Gas Administrator shall not issue or renew any registration permit or license to any person, firm, or corporation who is a resident of, or whose principal place of business is located in, a state other than Oklahoma unless the laws of such other state, and the rules and regulations of the authority governing the storage and dispensing of liquefied petroleum gas permit the operation of such business by citizens, firms, or corporations of Oklahoma under the same or substantially similar terms and conditions as those required for such operation in this state.