No, it has to be done within a couple of minutes, please search your email for mails from Xsolla (also check spam folder just in case)
If you 100% sure that the confirmation email was not sent to you, the fastest way to resolve the problem would be to contact Xsolla via 24/7 live chat at help.xsolla.com or email support@xsolla.com - they will re-sent the confirmation email to you