Rss feed for a category in wordpress
Typically, unless you've done some modifications to the core of Wordpress, you can add "/feed" at the end of a category URL and that will give you the RSS feed.
For instance, if you have a category "food" then your RSS feed would be example.com/food/feed
If you have a category base set under permalink settings /wp-admin/options-permalink.php then it would be example.com/your-category-base/food/feed
You can learn more about Feeds here:https://wordpress.org/support/article/wordpress-feeds/
Adding /feed to the end of any URL makes you access the feed functionality provided by WordPress, including for categories.