curl --location -g --request POST '{{BASE_URL}}/admin/orders//fulfillments//cancel' \
--header 'Content-Type: application/json' \
--data-raw '{
"no_notification": true,
"additional_data": {}
}'
+
it will be added to the default fields, using -
will remove it from the default fields. without prefix it will replace the entire default fields.additional_data
parameter.