In all probability you are using a custom taxonomy, and not the build-in category taxonomy. If this is the case, then the category parameters won’t work. You will need a tax_query to query posts from a specific term. (Remember, get_posts uses WP_Query, so you can pass any parameter from WP_Query to get_posts)
$args = [
'post_type' => 'product',
'tax_query' => [
[
'taxonomy' => 'my_custom_taxonomy',
'terms' => 7,
'include_children' => false // Remove if you need posts from term 7 child terms
],
],
// Rest of your arguments
];