In the APA publication style a doctoral thesis is called a dissertation and a master's thesis called a thesis. This reflects the academic terminology in the USA. In Australia, these terms are used interchangeably with thesis being the most common term. Theses is the plural form of thesis.
In-text reference
(Author, year)
OR
Reference list
Author, A. A. (2020). Title of thesis [Published thesis, Name of Institution]. Database or Archive Name. URL