We recommend to create a dedicated integration user. In any case, dedicated user or not, the user details must have access privileges to the Workday service Recruiting and the following operations: Get_Candidates, Get_Job_Requisitions and Get_Job_Postings.
The required credentials are not the same as the community login. The credentials are the Workday Account and password set up in Workday, not the same as the SSO password if any SSO mechanism is set up.
The provided user account also needs to be in a group that accesses to LaunchIntegration in addition to the Recruiting service.
If you ever need to extract the correct Base URL value follow the following steps:
In the Workday UI, search for “Public Web Services” in the search bar and load the “Public Web Services” report. On any of the web services, select the three dots to the right of the service name and take the action “Web Service” -> “View WSDL”