You're close, craft.app.sites
in Twig gives you access to the service craft\services\Sites
, which can be used to access specific sites. For example:
{# Get the primary site #}
{% set primarySite = craft.app.sites.getPrimarySite() %}
{# Get a specific site by handle #}
{% set myAwesomeSite = craft.app.sites.getSiteByHandle('myAwesomeSite') %}
{# Get an array with all sites #}
{% set allSites = craft.app.sites.getAllSites() %}
Use the class reference to find out what methods are available on the service.
I couldn't find a way, maybe it's close to craft.app.sites but don't know how to do it, of course sites have his own handle. Thank you.
A useful tip is to use the {% dd %}
tag to find out what a variable contains:
{% dd craft.app.sites %}
Put this anywhere in your Twig template and it will tell you which class the variable is an instance of. Then you can look that up in the class reference and take it from there.