Dot-twigrenderer extends Twig with a function that uses functionality from dotkernel/dot-authorization to check if a logged user is authorized to access a particular resource.
public function isGranted(string $permission = ''): bool;
The function returns a boolean value of true if the logged user has access to the requested permission.
Expanding on the example from the authentication extension:
{% if hasIdentity() %}
Welcome, {% getIdentity().username %}!
{% if isGranted({{ role }}) %}
{# your code #}
{% endif %}
{% endif %}