var tooltip = new bootstrap.Tooltip(tooltipTriggerEl); tooltip.config.html = true; code example

Example 1: bootstrap 4 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>
<button type="button" class="btn btn-secondary" data-toggle="tooltip" data-html="true" title="<em>Tooltip</em> <u>with</u> <b>HTML</b>">
  Tooltip with HTML
</button>

Example 2: how to show text at the time of hover in bootstrap

<div class="text-center my-3">
  <b-button v-b-tooltip.hover title="Tooltip directive content">
    Hover Me
  </b-button>

  <b-button id="tooltip-target-1">
    Hover Me
  </b-button>
  <b-tooltip target="tooltip-target-1" triggers="hover">
    I am tooltip <b>component</b> content!
  </b-tooltip>
</div>