How can I contribute to Wordpress plugin translation?
Take a look at: https://matomo.org/translations/
Translations are done on the platform https://www.transifex.com/
Great, thanks. I’m still confuse: translation from the Wordpress plugin (https://br.wordpress.org/plugins/matomo/) is at the main Matomo project? Or WP-piwik?
The completely Wordpress-specific parts (e.g. the wordpress plugin page) is translated using the Wordpress translation platform (so https://translate.wordpress.org/projects/wp-plugins/matomo/). While the Matomo application itself and everything related to it is translated on transifex.