Default value field one to many

I would like to be able to put a default value to this one to many field, how can I do it ?

 <field name="types" title="Types">
            <viewer> <![CDATA[ <strong>{{record.typesLabel}}</strong> ]]>
              <field name="typesLabel" readonly="true"/>

You can do like here : Record Action :: Axelor Documentation

The action-record has this : <field name="items" expr="action:default-orderline-record"/>. It allow you to init values in a one2many.

ok thanks i’ll look and come back later if i don’t understand everything lol