What is necessary to sign with a QES within DocuSign?

Beyond the general DocuSign license, you must purchase via DocuSign or a DocuSign reseller the “DocuSign Express SKU” and ask DocuSign support to enable the Swisscom PEN in the UI (this is the selection box for the Swisscom QES/AES). You also need to order the DocuSign connector via Swisscom Trust Services.