Under the header Electronic version(s), and related files and links you can add documents and links related to your publication.
This can be either a DOI-link or a regular URL leading to the full-text OR an actual file containing the full-text document.
This LibGuide has a separate page on how to how to upload a full-text file in Pure.
You can add a DOI or URL in a similar fashion, taking note of the following:
Use this option to add URLs that are related to the publication, but do not offer access to the publication full-text.
Those links will become visible on the VU Research Portal.
Use this option to add files that are related to the publication, but do not contain the full-text itseld.
Those files will not be shown on the VU Research Portal.