API connection problem

The install must open outbound HTTPS to WinStack.

Check

1. LICENSE_SERVER_URL is the public WinStack origin, no trailing path typos
2. Outbound 443 is allowed (some hosts block by default)
3. The server clock is NTP-synced
4. No MITM SSL inspection with a private CA the PHP stack does not trust
5. You are not pointing production at http://127.0.0.1:8090

php artisan tinker --execute="echo file_get_contents(config('license.server').'/robots.txt');"

If that fails, it is network, not your purchase code.

Note. WinStack does not whitelist customer IPs. If you must allow-list, open a ticket with the egress CIDR.