eBay token can be generated on eBay site for developers: https://developer.ebay.com/join/
After registration go to your account: https://developer.ebay.com/, then go to “Get your application Keys”. In Menu go My account → application keys, and click "Generate Production Keys"
Please note: there is a difference between production and sandbox system. If you want to use “Sandbox” for tests you need to generate “Sandbox Key”.
You will get DEVID, AppId and CertId. Now you can generate your eBay Token. Go to “Configure Settings”
On opened website click “User Tokens”:
then “Generate Token” (Please note: login using your seller account, not developer!). In case of sandbox token, login using your sandbox account.
Save token – Done!