If your application is for personal use and only needs to support one user, you only need one token. You can generate a single token for your application's user using the token tool.
Note : Please make sure your account is setup as per the guide before generating the token : https://go.developer.ebay.com/developers/ebay/documentation-tools/quick-start-guide
Steps to generate a new token :-
Note : The below example shows how to generate a token in Sandbox, the flow for Production is similar.
1. Open the link to access User Token tool :- https://go.developer.ebay.com/developers/ebay/documentation-tools/development-tools
2. Scroll to the bottom and click on 'User Token Tool'.
3. If you are not logged in to your the eBay Developer Account, it will take you to login page. Please enter your developer account credentials (login and password) and click on Sign In.
4. Once you are logged in, it will display a page to 'Get a User Token Here'. If you want to generate a token for a Sandbox user, ensure that you select the environment as sandbox.
5. Once you select the Environment as Sandbox, click on 'Sign in to Sandbox'
6. You should now see the Sandbox sign in page.
You need to enter the ebay User ID and Password. This is the account for which token needs to be accessed. So please enter the eBay User ID and Password.
Again, keep in mind that the eBay UserID and Password has to match the environment that you selected. If you want to generate a sandbox user token, then you need to enter the credentials for a Sandbox User.
If it is production, then it is a user that was created on the Production eBay site.
Note : Each token corresponds to a specific eBay user.
9. Click on 'I agree' on 'Grant application access: <appname>' page
10. Your token has been generated and you need to simply copy this token and paste it in your code.
Note: Your token is valid for 18 months. For future reference, please save your token in a secure place.
For more information, please refer to the doc : http://developer.ebay.com/Devzone/guides/ebayfeatures/Basics/Call-SandboxTesting.html