Curl to Backup API link always timeout

[Yusoff]

Hi All

I'm new to OPNSense and been playing around with it for a about a day.
I'm trying to get automated backup working using API.

I've installed the os-api-backup, created a group called backup with Backup API privileges, created a user and assigned to the backup group. I went through several post in the forum and used a script that was shared (see this https://forum.opnsense.org/index.php?topic=18218.0)

However I'm not getting any result.
I ran the curl command directly and noticed I'm getting time out error.

curl -u "keyabc":"secret123" https://1.2.3.4/api/backup/backup/download
curl: (7) Failed to connect to 1.2.3.4 port 443: Connection timed out

When I supply the URL to the browser, the file config.xml downloads.
I am able to run curl from my Laptop (where I access the URL link directly).
I get time out in my Linux Server (same subnet as firewall LAN)

The firewall only has two default rules:
        IPv4 *   LAN net   *   *   *   *   *   Default allow LAN to any rule      
        IPv6 *   LAN net   *   *   *   *   *   Default allow LAN IPv6 to any rule

Is there something else that needs to be done?