Use this as your function instead:
add_filter( 'generate_post_author_output', function( $author) {
printf( ' <span class="byline">%1$s</span>',
sprintf( '<span class="author vcard" itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author">%4$s<a href="%1$s" title="%2$s" rel="author"><span class="author-name" itemprop="name">%3$s</span></a></span>',
esc_url( get_author_posts_url( get_the_author_meta( 'ID' ) ) ),
esc_attr( sprintf( __( 'View all posts by %s', 'generatepress' ), get_the_author() ) ),
esc_html( get_the_author() ),
get_avatar( get_the_author_meta( 'ID' ) )
)
);
if ( ! is_single() && ! post_password_required() && ( comments_open() || get_comments_number() ) ) {
echo '<span class="comments-link">';
comments_popup_link( __( 'Leave a comment', 'generatepress' ), __( '1 Comment', 'generatepress' ), __( '% Comments', 'generatepress' ) );
echo '</span>';
}
$categories_list = get_the_category_list( ', ' );
if ( $categories_list ) {
printf( '<span class="cat-links"><span class="screen-reader-text">%1$s </span>%2$s</span>',
esc_html_x( 'Categories', 'Used before category names.', 'generatepress' ),
$categories_list
);
}
} );
Let me know ๐