No. Signers don’t need to create a Dropbox Sign account to sign a document. When you send a signature request, the signer receives an email allowing them to open, review, and sign the document even if they don’t have an account.
In some cases, signers may see a prompt to finish setting up an account when they sign up or reset their password. Creating an account is optional. Signers can still continue to review and sign the document without setting up an account.
After all signers have signed the document, they'll receive a copy of the signed document (depending on their notification settings).