To easily test and integrate with the SignRequest API you can activate a Sandbox team account and generate an API token. While using this specific API token all the documents sent are for free, but will contain a watermark.
Once you're ready to go into production you can either create a new team or switch the Sandbox team account into a production environment by using the 'Convert to production team' button on the team settings page. The watermark will then be removed. To switch to a production environment you will need to already have or select one of the API plans. These can be selected online with a credit card or SEPA mandate. Please submit a ticket if you need any help with that.
Activate a Sandbox team account
Log into your personal account and make sure you're not active in a team account. Otherwise you'll not be able to create a Sandbox team account. To switch between your personal and team account(s) have a look here.
Use this specific link to activate a Sandbox team account: Create Sandbox team
The link is also available in the API docs.
Generate the API token
1. Fill in the necessary fields on the team page.
2. Click 'Create team'.
3. Now the API settings will become visible.