Which privilege/role is necessary to add a user to sign a contract?

Summary:

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We need to add as a signatory a user who will not use the contract module to create/manage contracts, but is a user, who must view the contract document and sign them through the integration with Docusign. Which privilege/role is necessary to be able to add the user with the "Signer" role?

Do you need to be a buyer or contract administrator?

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