Change path in Save As modal from a Drive

I’ve got a custom extension opening files from a custom API (this is read only), using a Drive object created like this:

  const drive = new Drive({
    apiEndpoint: 'new_api/notebooks',
    name: 'newApiNotebooks'

The problem is that when I ‘Save As’ a notebook, in the modal the drive name is added to the path, and so it shows ‘newApiNotebooks:my_notebook.ipynb’.

I’d like to modify this path (remove the drive part) but I can’t find what to modify. Also path attributes (in context or session objects) are read-only. Could somebody help?