Here are links to official articles about testing on projects:
http://bit.ly/3nJ66JE - key info about UAT understanding
http://bit.ly/410OpEp - UAT phase on the project - details about how to handle UAT on the project
http://bit.ly/3KObqEL - how to create UAT test cases - details about UAT test cases and how they should be prepared
https://www.pricefx.com/learning-center/myths-and-truths-about-software-testing/ - myths about testing when there is a discussion about QA with the customer