Update Product's warehouse on-hand quantity

Am trying to update a product’s warehouse on-hand quantity using php api. I tried multiple ways but couldn’t update it.
curl_setopt($ch, CURLOPT_URL, "https://api.ordoro.com/product/SKU/warehouse/WAREHOUSE);
Where should I pass my new on-hand quantity?

You need to pass an object or a dictionary to your curl request that would have "on_hand": units units would be quantity you want to set.