How to insert raw html (hyperlink) to email message

Hi! I used in alert_resources.yml the code like this:

template: |
    {{ define "alert.additional_details" -}}  
========================================================================
       {{ if .DashboardURL }}
      - <a href="{{ .DashboardURL }}">Dashboard</a>
      {{ end -}}

Also I tried:

[Dashboard Url]({{ .DashboardURL -}})

Both returns me the output as it is like:

[Dashboard Url](``http://myurl``)

And I want to see hidden hyperlink like this:

изображение