“Previous Posts” Stopped Working

I have a link for “previous posts” at the bottom of my blog, https://urltea.com/15bh , which recently stopped working, and now only shows the 5 newest posts when clicked. I’m using this code on my main index template:

<?php next_posts_link(‘« Previous Entries’) ?>
<?php previous_posts_link(‘Next Entries »’) ?>

Any help would be greatly appreciated! Thanks for looking!