Craft CMS 3 - Entries field, getURL
entry.featuredProjectLink is not an element or an array of elements, it is an object of type MatrixQuery in order to fetch elements you have to use the .one() or .all() function

&lt;a href="{{ entry.featuredProjectLink.one().getUrl() }}"&gt;


Element Queries

Relations -> the "Going Through Matrix" part is the thing you want