Sometimes, one has a BibTeX/biblatex entry with abbreviated short names:
Now, one wants to have the full first names. In case, there is a DOI available, this is as simple as the following steps:
Determine the DOI: Switch to the "General" tab and click on "Look up DOI"
Fetch BibTeX data from the DOI: Click on "Get BibTeX data from DOI"
A popup appears. Select which data you want to merge into the eixting entry
Now the first names are expanded: