Can't find language files

There is a function called get-text in wordpress which changes the text to other languages. But it changes that text to overall site wherever it appears on either front-end or the back-end. For example, [To change the text ‘Home’ to ‘Accueil’]

function theme_change_comment_field_names( $translated_text, $text, $domain ) {
        switch ( $translated_text ) {
            case 'Home' :
                $translated_text = __( 'Accueil', 'text-domain' );
                break;
        }
    return $translated_text;
}

See for the reference: https://codex.www.ads-software.com/Plugin_API/Filter_Reference/gettext

Hope that helps!

Hi, translate says:
“This plugin is not properly prepared for localization (View detailed logs on Slack). If you would like to translate this plugin, please contact the author.”
https://translate.www.ads-software.com/projects/wp-plugins/weekly-class-schedule