Go to Insurance references . 

Double-click (or modify button) on the CAF line.

or load a profile :

and fill in all the fields.  Example :

If the fund pays the allowances directly to the employees, check the box "Child allowances paid by the compensation office".

If you establish salaries in several cantons, you will have to create as many funds as necessary. In this case, use the CAF 2nd canton or click on the add button if there are not enough in the table.

Go to Settings - Salary items

Make sure that the correct contract is selected on the Computation Elements tab (especially if there are several CAF items and several cantons).

It is possible to create as many funds (and items) as necessary according to the particularities of the company.

See here how to manage the item(s).