how to adjust style to tooltip bootstrap code example

Example 1: bootstrap tooltip

<button type="button" class="btn btn-secondary" data-toggle="tooltip" data-placement="top" title="Tooltip on top">
  Tooltip on top
</button>
<button type="button" class="btn btn-secondary" data-toggle="tooltip" data-placement="right" title="Tooltip on right">
  Tooltip on right
</button>
<button type="button" class="btn btn-secondary" data-toggle="tooltip" data-placement="bottom" title="Tooltip on bottom">
  Tooltip on bottom
</button>
<button type="button" class="btn btn-secondary" data-toggle="tooltip" data-placement="left" title="Tooltip on left">
  Tooltip on left
</button>

Example 2: bootstrap tooltip

$(function () {
  $('[data-toggle="tooltip"]').tooltip()
})