First, take a look at the mapping between options properties and widget elements in these three visuals below.
To edit Privacy request widget design, you need to edit the layout-component dsar_form by sending a PATCH request on /widgets/layout-components/{layout-component-id} and specifying options in options property.
Be careful when you are editing the options property. This is a JSONB and by design, you need to fill in every properties already added every time you edit this object.
We have gathered all elements and their options in the following object. You can use it to edit the dsar_form options by sending a PATCH request on /widgets/layout-components/{layout-component-id}.