I clicked on "Extend" to extend the date of my API. It asked to type "I UNDERSTAND". I did so. The date increased by 30 days. But no money got deducted from any where. I had money for one month extension in my wallet. I tried again to just check. The date again increased by 30 days but still no money got deducted.
It seems like you have connected Zerodha account to your developer console account. Money gets debited from your Zerodha account and the debit instruction will show up in the trading ledger by tomorrow EOD.
Since you have linked to the Zerodha client id, money will be deducted from the Zerodha account, if you don't have credits on developers console. Auto-renewal also happens if you have linked the Zerodha account.
Auto-renewal also happens if you have linked the Zerodha account.