Many Publishers assign a Digital Object Identifier (DOI) to journal articles and other types of documents. A DOI is a unique alpha-numeric code given to individual online works. The DOI usually appears at the top of the article or in the database record for the article and begins with https://doi.org or http://dx.doi.org or DOI:. The DOI identifies content and provides a persistent link to its internet location.
At the moment, not all publishers provide DOIs. Some library databases such as PsycINFO provide a DOI for each article. When a DOI is provided, your should provide it at the end of your APA reference. If given, the DOI takes precedence over the URL.
Some databases do not provide DOIs. If the article you are citing does not include a DOI "from most academic databases, do not include a URL or database information in the reference because these works are widely available. The reference should be the same as the reference for a print version of the work."
If there is no DOI provided, try searching CrossRef.org, a free DOI lookup.
(Publication manual of the American Psychological Association, 7th ed., 2020, p. 299)
APA suggests that when DOIs are available, you include them for both print and electronic sources.
APA provides these guidelines for including DOIs and URLs in references:
(Publication manual of the American Psychological Association, 7th ed., 2020, pp. 298-299)
"Follow these guidelines to format DOIs and URLs
(Publication manual of the American Psychological Association, 7th ed., 2020, pp. 299-300)