I don't think you'll have any trouble giving it away for free. As long as it's in relatively good condition, someone will surely be interested in it. You can use any platform normally used to sell stuff (Facebook marketplace, eBay, etc.) and place it without a price and mention in the description that you are giving it away for free. If you want to get rid of it, you can also use a disposal bin. The companies behind them are responsible for recycling it, and they do it according to the existing regulations, therefore, you can be sure it will be done eco-friendly.