After registration I don't receive any activation link

-- HikaShop version -- : 3.6.2
-- Joomla version -- : 3.8.6
-- PHP version -- : 5.6

After registration the user doesn't receive any activation link.
So, no user, no order.

What could be the issue?

Hi,

First, check in Customers>Emails history.
If you see the email there, HikaShop sent it.
Then either it's in the spam of the receiver, or it has been rejected by the receiver email server or there was a problem in the email server sending the email on your hosting.