Does a tooltip require close button?

Agree, if it is a static tooltip that appears after a click (on a button) then a close button should be added and the tooltip should disappear when an other element is clicked. Tooltips that appear on hover don't require close buttons.

1. How do I add a close button to tooltip?
2. Can tooltip have buttons?
3. Should tooltips be clicked or hover?
4. Should buttons have tooltips?

How do I add a close button to tooltip?

The Tooltip provides an option for closing its content with a button. By default, the Tooltip closes when the user moves the mouse pointer either outside the tooltip or outside its target, and does not explicitly render a Close button. To add a dedicated Close button to the Tooltip, set its closable property to true .

Can tooltip have buttons?

To add a tooltip to a button you can use the title attribute on the button element. This will create a tooltip when the user hovers over the button element. And it's really as simple as that, be sure to leverage the use of tooltips to provides better context for your users.

Should tooltips be clicked or hover?

Support both mouse and keyboard hover.

Tooltips that appear only on mouse hover are inaccessible for users that rely on keyboards to navigate. Be inclusive in your design and ensure that your tooltips are accessible via keyboards.

Should buttons have tooltips?

If you're introducing the button as a new element & needs to draw users' attention you should use tooltip. It will help users to learn. *If the button explains itself clearly, we should not use tooltip.