Does Square supports webhook notifications for online checkout events?
I have created one online checkout link to accept payments from my customer but not sure how to associate by checkout link with webhook?
We will trigger payment and order event notifications when a customer checks out with a link that you created from the Seller Dashboard. If you create the links with the Checkout API we will trigger an order event before you pay for the checkout, but any link created by the API is a one time use link. 
Bryan - How can I test payment with sandbox environment? And Also does it mean there will be no use of Application id and Access token.
And I tried real payment with checkout link which I have created of amount $1 but there was no event found in webhook logs. could you please guide me.
We have generated checkout links manually using our dashboard, so will it triggered our webhook or not?
At this time there isn’t a sandbox for Square online store or the checkout links created in the Dashboard. You’ll have to test in production to trigger the events.
Bryan - could you please guidd us on this, I tried real payment with checkout link which I have created of amount $1 but there was no event found in webhook logs.
That should have triggered a payment and an order webhook event. What’s your application ID?
Here is the App ID: sq0idp-8axmY45RNFAN-_xBFuHwmA
One more thing, Is there any way to know which customer has made the payment as the payment link which we have generated is through dashboard and it will be same for all customer/users. So how can we identify the customer through the data which webhook will send to our server?
I took a look at your webhooks logs and I see that the webhooks were triggered. Your server is responding with a 405 instead of a 200.
Also if you want to know who paid for the link you’ll take the customer_id from the payment and call the Customers API to get the customer details.