Hello @neethujkp,
If Maestro is already supporting DocuSign or integrates with DocuSign Apps Launcher, you don't need an add-on.
If you're using DocuSign Apps Launcher from App Exchange it will be not required to obtain Salesforce add-on if you don't need any addition features outside your Account Plan or if you wish to customize your workflow.
If you need paid or advanced features, maybe you need an account plan upgrade or a Salesforce Connector.
You can confirm this with our Account Services or Sales Teams, because depending on your plan the Salesforce Connector can be included and in this case you don't need to acquire it separately, or depending on the features you want to use and how to set up them the necessity of acquiring an add-on may arise.