If you can avoid using a plugin, just do it. Because less is more.
Here is a simple tool for creating custom Metabox/Custom Fields for your posts or post types.
Copy and paste this code on your snippet plugin or functions.php in your theme. 😊
This only creates just a simple custom field but most of the time that’s the only thing we need anyway.
But wait there is more. You can generate multiple metabox fields for the same post type as well. Just generate as many as you want and paste the code separately they will just work 😊