Where is Create Voucher

Dear Sophos Community Experts

I am new here and also to Sophos.

Would any of you kindly enlighten me no the following?  Would I specifically need to deploy/use a Sophos wireless access point in order, to create vouchers? I cannot see a 'create voucher' button anywhere under Protect > Wireless > Hotspot | Hotspot Definitions.

Background Details

Devices:

1. Sophos Firewall XG310 (Appliance) Firmware 18.1.0;
2. Unifi AP-AC-LR (Access Point) + Unifi Controller

• I have created necessary interfaces, DHCP and DNS (on the XGFW)
• Have created relevant IP hosts/network under Systems > Hosts and Services  > IP Hosts
• Relevant firewall rules have also been created on FWXG310 to allow traffic to and from respective networks/services. Protect > Rules & Policies > Firewall Rules
• I have configured (V)LANs to pass between the FWXG310 and Unifi controller/devices.
• I have also done some configuration under Configure > Authentication > Web Authentication
• I have created WLAN SSID (open access; no passphrase/encryptions) on the Unifi Access points. When I connect to the SSID and try to access the internet, I am redirected to the Sophos FWXG310's hotspot authentication page showing/prompting 1) Terms of Use Agreement Acceptance 2) an input box for the voucher.
• I have also created and assigned users to create vouchers (on XGFW310) but even then, when I log in with these designated users, the result is the same 'create voucher' button or feature cannot be found.
• where can I locate this 'Create Voucher' button?

I have been digging around for five days on this forum, the user assistance guide, the Sophos techvids, and elsewhere; however, I have not come across something that is specific to my case hence I am asking here. I believe I have followed most of the official guides that are available but I may have missed some important detail.  I would appreciate any help/pointers.

Thanks in advance