Vaping using a delta 8 disposable is legal in all states and territories where delta 8 is legal.
In the US, the Delta 8 THC cannabinoid is federally legal. However, some states have gone ahead to ban the sales of the substance.
The thirteen states in which vaping delta-8 THC is illegal include: Utah, Alaska, Vermont, Arizona, Rhode Island, Arkansas, New York (borderline), Montana, Colorado, Mississippi, Delaware, Lowa, Idaho.
It would help if you were conversant with your local state's delta-8 laws before using the substance. You may consult the local authorities for clarification wherever you find conflicting delta-8 THC legal frameworks.