This is required for the icat.server to see a new authenticator. If you are just updating an existing restful authenticator then the run.properties of the icat.server will not need changing.
Assuming that you still have the installation directory for icat.server then edit the run.properties to refer to the new authenticator and type: ./setup install
Users should be added by manually adding them to the database table PASSWD. This has two columns, one for the username and one for the password. The password may be entered as clear text without a leading "$" or a cryptographic hash of a password may be stored.
A password hash must start with a "$" character and be in Modular Crypt Format. The supported hash algorithms are MD5, SHA-256, and SHA-512. Do not use MD5 because it is insecure.
Use the following command to create a SHA-256 hash: openssl passwd -5
The mkpasswd(1) utility can also be used. It is provided by the whois package on Debian-based systems: mkpasswd --method=SHA-256
Use testicat (which is installed with ICAT) with one of the entries in the database PASSWD table. It should report that it logs in but may or may not have the permission to run the rest of the test. If it does not report that it has logged in then please check the server.log and the authn_db.log files which can both be found in the logs directory below your domain.