Woocommerce: How to change the add to cart text in a certain category? [closed]

You can use the has_term function to check for the desired term.

function add_cart_button_replace() {
    global $product;
    $link = $product->get_permalink();

    $button_text = __('+show OFFER', 'woocommerce');

   // check if the current product has a "product-category" of "free-products"
    if(has_term('free-products', 'product_cat', $product->get_id()))
        $button_text = __('+choose me', 'woocommerce');

    echo do_shortcode('<a href="'.$link.'" class="button addtocartbutton">' . $button_text . '</a>');

}

You can also learn more about has_term function.

Update: change product-category taxonomy to product_cat as per your comment.