I have already contacted a custome care of Envato. And they reply it with this message.
Hi Purnendu,
Thank you for reaching out and I hope you’re doing well. My name is Levi, from Envato Customer Success Team at your service.
Sorry for the issues you are having trying to purchase. We do not handle any of the monetary transactions made to the site, these are done by PayPal, Skrill, or your credit card provider. In most cases, you will need to contact their support to resolve issues encountered while checking out.
PayPal support can be contacted via https://www.paypal.com/us/webapps/helpcenter/helphub/home/
Skrill support can be contacted via https://www.skrill.com/en/support/
Though we can’t help transactions process successfully, I have some helpful suggestions accumulated over time from our users:
Occasionally buyers have reported having issues checking out. Fortunately, they’ve also reported that it’s not a permanent issue so if you clear your browser cache and cookies, and then try the transaction again, you’ll likely be able to successfully purchase the item you’re interested in.
We know that our users, also, report a greater success rate for purchases when making sure that their details match their PayPal, Skrill and financial institution details (for example, make sure that your registered email address here is the same as the email address that you’ve used for PayPal).
Some other suggestions that may be helpful are to attempt your purchase from a mobile device like a smartphone, or, try using an alternate payment source such as a different credit card.
Lastly, we’re an Australian-based company. It’s not uncommon for Credit Card issuers to block an overseas payment until you’ve approved it. You might need to contact your card issuer to see if they’ve added any blockers to your card.
Warmest regards,
Levi