electrical - 240v L14-30R wiring air compressor switch - Home Improvement Stack Exchange

I purchased a Campbell Hausfeld 6 hp 60 gallon DK400121AV. It's supposed to run on 240v, but the guy I bought it from had a 120v plug wired to it. How do I wire a L14-30P plug to the pressure switch?

prong dryer cord adapter from

Generator Pigtail Adapter Cord. NEMA L5-30P 3Prong 30Amp 125Volt Locking Male Plug to NEMA L14-30R(Hots bridged) 30Amp 125/250Volt 4Prong Locking

AC WORKS Generator to Transfer Switch L14-30 Inlet Box Adapter (L5-30 30Amp 3-Prong to L14-30-Flexible)

electrical - How do I wire this motor with 240V? - Home Improvement Stack Exchange

3 different ways to wire a compressors Pressure Switch

electrical - Plugging compressor into 240v dryer plug (NEMA 10-30R) - Home Improvement Stack Exchange

electrical - Plugging compressor into 240v dryer plug (NEMA 10-30R) - Home Improvement Stack Exchange

electrical - How do I wire this motor with 240V? - Home Improvement Stack Exchange

electrical - Can I share a 240V outlet between two devices? - Home Improvement Stack Exchange

3 different ways to wire a compressors Pressure Switch