Here are some examples.

Report: Trump Demands Loyalty Oath From Job Seekers Who Criticized Him During Election

https://www.thedailybeast.com/trump-demands-loyalty-oath-from-job-seekers-who-criticized-him-during-election

Fear and Loyalty: How Donald Trump Took Over the Republican Party

https://www.nytimes.com/2019/12/21/us/politics/trump-impeachment-republicans.html

Trump defends loyalty pledges at rallies, ‘surprised’ by Hitler comparisons

https://www.yahoo.com/news/trump-loyalty-pledge-hitler-video-153312237.html

What Trump really means when he demands ‘loyalty’

https://www.washingtonpost.com/blogs/plum-line/wp/2018/02/01/what-trump-really-means-when-he-demands-loyalty/

TRUMP IS TAKING HIS DEMAND FOR LOYALTY TO THE NEXT LEVEL

https://www.vanityfair.com/news/2020/02/trump-is-taking-his-demand-for-loyalty-to-the-next-level

Trump Demands Loyalty and Inspires Very Little

https://politicalwire.com/2020/01/29/trump-demands-loyalty-and-inspires-very-little/

Trump orchestrates final loyalty test in dying bid to subvert election

https://www.politico.com/news/2020/12/22/trump-final-loyalty-test-election-450183

Bonus

FBI warns against Nunes memo release amid Trump loyalty demands

https://www.msnbc.com/rachel-maddow/watch/fbi-warns-against-nunes-memo-release-amid-trump-loyalty-demands-1150937155652

The Nunes memo memo turned out to be accurate BTW.