What element is necessary for citing a source with a DOI in APA format?

Including the DOI (Digital Object Identifier) at the end of the citation is crucial in APA format because it provides a permanent link to the source, allowing readers to directly access the material. This practice enhances the reliability and accessibility of academic work, as the DOI remains consistent even if the location of the source changes. In APA style, the proper format for a DOI is typically structured as a URL link (e.g., https://doi.org/...) when it is listed, ensuring that it is easily clickable for users. This element of citation is fundamental to the integrity and traceability of research sources in academic writing.