Invenio-Previewer is on PyPI so all you need is:
pip install invenio-previewer
Invenio-Previewer depends on Invenio-Assets for assets bundling and Invenio-PidStore and Invenio-Records-UI for record integration.
You will normally use it in combination with files. You can install the extra Invenio modules Invenio-Files-REST
and Invenio-Records-Files by specifying the files key in extras:
pip install invenio-previewer[files]