Open Connected marketplaces and choose Reverb. Follow the link to your Reverb API settings, create a personal access token and paste it into Personal access token. Choose Save token. Treat the token like a password; do not include it in a listing or support screenshot.
Open an item in Musical Instruments & Gear, choose Sell, then Reverb. Check the photos, title, description and condition. Check the displayed currency, price and worldwide shipping charge; zero means free shipping. Choose Publish on Reverb and inspect the live listing. Buyers pay and message you through Reverb. If blocked, read the message and check your plan.