In APA 7th Edition, the rules differ depending on how many authors you have:
1-2: Always mention the names of all authors
3-20 authors;
In text, you only use the first author's surname and abbreviate the rest of the list with "et al." (Latin for "and others").
In your reference list, you list all of the authors (up to 20).
20+ authors (regardless of how many);
In text, you only use the first author's surname and abbreviate the rest of the list with "et al.".
In your reference list, you list the first 19 authors and the last one, using an ellipses (...) to show that some authors have been omitted (do not use an ampersand &).
Examples of intext and reference lists are available here.
We acknowledge the Australian Aboriginal and Torres Strait Islander peoples as the first inhabitants of the nation and acknowledge Traditional Owners of the lands where our staff and students, live, learn and work.
