I can’t find any REST API to update and view contact password that exists under “Additional Info” section. How i can update contact password with help of REST API?
Due to security concerns and the legacy contact passwords not being in safely single-direction encrypted storage (as we do for Keap Account credentials and our internal secret stores) we have determined that we will not be supporting those fields going forward.
For now, you can retrieve and set those values via the XML-RPC, but I would take the opportunity to restructure your codebase to avoid using them and to use a secure identity-management system instead.
As Tom said, not a good idea to keep passwords within Keap.
For your reference, in the XML-RPC API, you need to query the “Contact” record “Password” field.
You need either use the Data Query API function, or the Load Contact API function instead.