It offers the following configuration properties:

password-character-set
Defines the character sets that can be used when generating passwords. Each character set should consist of a name followed by a colon and the set of characters that set contains (for example, alpha:abcdefghijklmnopqrstuvwxyz or numeric:0123456789). Multiple character sets can be configured.
password-format
Specifies the format that should be used when generating passwords. This should be a comma-delimited list in which each item is the name of a character set followed by a colon and the number of characters to include from that set (for example, alpha:3,numeric:2,alpha:3 indicates that the generated password should consist of three alphabetic characters followed two numeric digits and three more alphabetic characters).