We do not prefer any particular digital signature, because this depends, as in many cases, on who, what, why use how. Here is a list of providers where you can get inspiration.
- DocuSign: https://www.docusign.com/
- SignRequest: https://signrequest.com/en/
- PandaDoc: https://www.pandadoc.com
- Libreoffice digital Signature https://help.libreoffice.org/6.1/en-US/text/shared/guide/digital_signatures.html?&DbPAR=WRITER&System=MAC