The most common reasons a Lightning Network withdrawal fails:
1. Insufficient inbound capacity leading to the receiving wallet
2. No route to the receiving wallet was found
3. The invoice has no pre-set amount defined (in sats)
4. Insufficient balance on your Bitaroo account
The withdrawal will either fail immediately or go to a 'pending' state which will eventually succeed or fail, but that may take up to 24-36 hours.
Should the payment fail, the entire withdrawal amount will automatically return to your Bitaroo account. No fees will apply.