X-Sim is designed to share help in the community by uploading your simulator setup to a database. Other user can download and try this settings.
If you really need a offline version, you can donate for a key, this means you stop sharing and offer some money for a non community edition.
Donating can be done with the big paypal donate button on top of the homepage. Paypal may also support some credit cards. There is no other wire transfer option.
Follow this link for details which version you need:
You will get a mail response with an activation instruction to your donation in about 24 hours.
For your information, this is a free donation from you. X-Sim comes “as it is” with no additional warranty or bill. Only reseller editions get a invoice because of the work with adding own logos and the setup default programming.