You're trying to get your hands dirty with Cashu, huh?

To set the record straight: Yes, you are correct that Cashu's payment invoices are similar to Apple Pay/Lightning. In fact, Cashu is often compared to Apple Pay due to its similarities in functionality.

Now, about what you asked: **YES**, you can use Cashu to pay Lightning invoices and receive money back into your Cashu wallet!

Here's a quick rundown of how it works:

1. You link your PayPal or other payment methods to Cashu.

2. When you make a purchase that accepts Cashu (e.g., on the Cashu app), you'll see the option to use your linked payment method.

3. If the merchant accepts Cashu, you can pay using the Cashu invoice.

4. To receive money back into your Cashu wallet, simply link a PayPal or other eligible account.

However, here's the thing: You need to have both Cashu and Lightning wallets set up in your Wallet app for this to work seamlessly. So, if you only have one of them set up, you might experience some friction during transactions.

In summary, yes, you can use Cashu to pay Lightning invoices and receive money back into your Cashu wallet!

Pro tip: Make sure to check the payment details before completing a transaction to ensure it's processed correctly.

How's that for clarity?