APA describes how to properly cite doctoral dissertations and master's theses in section 10.6. APA distinguishes between unpublished and published items.
In brackets after the title, list the document type such as a doctoral dissertation or master's thesis.
If the item is unpublished, insert the word unpublished before the document type. Then after the bracket, list the degree-granting institution as shown in the example below
R: Windham, R. N. (2006). On forming leaders for ministry in the postmodern world: A model based on the writings of Henri J. M. Nouwen [Unpublished doctoral dissertation]. Azusa Pacific University.
P: (Windham, 2006, p. 120)
If the thesis, dissertation, or doctoral project is published such as in a database like ProQuest Dissertations or Theological Research Exchange Network that information needs to be included.
R: Williamson, P. A. (2007). Missionary self-identification in Muslim contexts (Publication no. 001.1129) [Master's thesis, Dallas Theological Seminary]. Theological Research Exchange Network.
P: (Williamson, 2007, p. 55)
If the dissertation is available through an institutional repository or another online resource that is not a database, include the name of the online resource and the URL of the specific paper.
R: Kim, S. (2018). The effect of a Bible based annualized protocol targeting attachment to God in anxiety and stress [Doctoral dissertation, Liberty University]. Scholars Crossing The Institutional Repository of Liberty University. https://digitalcommons.liberty.edu/doctoral/1646/
P: (Kim, 2018)