I need a german Stemmer processor for my Search API in Drupal 8. Snowball Stemmer seems to be the right choice, but I can't get it to work. Snowball Stemmer requires a library. I think it is the wamania/php-stemmer.
It should be installed with composer but I am not familiar with composer.
I tried following:
composer require drupal/snowball_stemmer
But I am getting
[InvalidArgumentException]
Could not find package drupal/snowball_stemmer at any version for your minimum-stability (stable). Check the package spelling or your minimum-stability
I tried also:
composer require drupal/snowball_stemmer --dev --ignore-platform-reqs
but getting the same error.
How I can install Snowball Stemmer with a german library?