in my exemple, “CPT” stands for the slug of your custom post type.

First step :

Using the link of “create new CPT” to add the information of category. for exemple the result would look like http://server/wp-admin/post-new.php?post_type=CPT&category=potatoes

Second step :

Using the hook save_post_CPT to preset the category. it would be something like that :

add_action("save_post_CPT", function ($post_ID, $post, $update) {

    if ($update) {
        // it's not a new object
        return;
    }

    if (!isset($_GET["category"])) {
        return;
    }

    // setting the category
    wp_set_object_terms($post_ID, $_GET["category"], "category", TRUE);


}, 10, 3);