You enter new passwords into the database by selecting the key icon in the software. The key with the pointer down is used for new entries, you can edit it with the key and pen. You can delete entries with the key and X symbol.

When creating (or editing) a key, you can again use the cube symbol to generate a password randomly. Since you usually don't have to enter the password manually, it is a good idea to exceed the requirements of the password policy, for example by using 24 characters from the three categories a-z, A-Z, 0-9.