After you complete checkout for HostStack hosting, watch the inbox on your account email for the welcome message. It typically includes your cPanel URL, username, and pointers to reset your control-panel password.
Billing, invoices, and ticket history live in the HostStack client area at client.hoststack.pro. From there you can open services, pay renewal invoices, and request migrations — independent of cPanel.
If something is missing
Spam folders and filters sometimes hide transactional mail. If you still cannot locate credentials after ~15 minutes, log into the client area and open a ticket so HostStack support can resend or verify delivery paths.