Ankle sprains typically happen when the ankle is twisted in an awkward position, overstretching the ligaments present as a result. Please see below for more information.

https://www.sgh.com.sg/content/dam/singhealth-web/sgh/imported-assets/assets/patient-care/specialties-services/physiotherapy/publishingimages/pages/patient-resources/Lateral%20Ankle%20Sprain%20(Jan%202021).pdf