The popover API adds [3 new attributes ](https://developer.mozilla.org/en-US/docs/Web/API/Popover_API#html_attributes) to some/all elements that are not present in the TS DOM types yet: 1. popover 2. popovertarget - exposed in JS as popoverTargetElement 3. popovertargetaction - exposed in JS as popoverTargetAction