Want to get posts from category slug - wordpress

Question

I'm working on a project and getting same results in different category slug. Please help what I'm doing wrong here.
$act = $_POST['act'];
$args = array(
'posts_per_page' => 100,
'offset' => 0,
'category' => $act,
'orderby' => 'post_date',
'order' => 'DESC',
'post_type' => 'product',
'taxnomy' => 'product_cat',
'post_status' => 'publish');
$myposts = get_posts( $args );
global $product;
global $wpdb;
foreach ($myposts as $key => $value) {
$id = $value->ID;
echo '<li class="product type-product status-publish has-post-thumbnail first grid with-hover add-hover open-on-mobile with-border span3 featured shipping-taxable product-type-simple product-cat-accommodation-durban product-cat-accommodation-battlefields product-cat-battlefields product-cat-comfortable-accommodation-durban product-cat-comfortable-accommodation-battlefields product-cat-durban instock">';
echo '<div class="product-wrapper">';
echo '<a class="thumb" href="'.get_permalink( $id ).'">';
$post_thumbnail_id = get_post_thumbnail_id($id);
$post_thumbnail_url = wp_get_attachment_url( $post_thumbnail_id );
echo '<img src="'.$post_thumbnail_url.'" />';
echo '</a>';
echo '<h3>'.get_the_title( $id ).'</h3>';
echo '</div></li>';
}

Answer 1

<?php
$slug = "category-b";
$args = array(
'posts_per_page' => -1,
'tax_query' => array(
'relation' => 'AND',
array(
'taxonomy' => 'product_cat',
'field' => 'slug',
'terms' => $slug
)
),
'post_type' => 'product',
'orderby' => 'title',
);
$the_query = new WP_Query( $args );
foreach ($the_query->posts as $key => $value) {
print_r($value->ID);
}
?>

Answer 2

After careful consideration, I found the root of the problem:
The category needs to be an ID, quoting Wordpress:
Note: The category parameter needs to be the ID of the category, and
not the category name.
Note: The category parameter can be a comma separated list of
categories, as the get_posts() function passes the 'category'
parameter directly into WP_Query as 'cat'.
Note: The category_name parameter needs to be a string, in this case,
the category name.
Taxonomy is not well written, is "taxonomy" and not "taxnomy". Also, you can remove it from there as it's not filtering anything.