Hello john smith…
Welcome to optiwave…
There is no licence issue for the first trial month period…
You should download the software from the link
https://optiwave.com/category/products/system-and-amplifier-design/optisystem/
It is a trial version of the software and will be having a 30 day evaluation period and after 30 days your access will be terminated if you do not buy a license..
with regards
tanveer