#hugo needed a new way to open ext. links in new tab. Found no example if own site is in links of older posts: layouts/_default/_markup/render-link.html

<a href="{{ .Destination | safeURL }}"{{ with .Title}} title="{{ . }}"{{ end }}{{ if and (strings.HasPrefix .Destination "http") (not (strings.HasPrefix .Destination "https://kmj.at")) (not (strings.HasPrefix .Destination "http://wmv7y4mytoraddy.onion")) }} target="_blank" rel="noreferrer noopener"{{ end }}>{{ .Text | safeHTML }}</a>

work