If the store you’re exporting has 100 products or fewer, this tool is free with no time limit and no trial period that runs out - it’s simply free, every time, for as long as you use it.
Bigger catalogs need a Pro license to remove the 100-product cap, and that is a subscription - but nothing stops you from subscribing for a single month to finish one large export or migration, then cancelling. There’s no minimum term.
Either way, the tool itself never phones home beyond checking a license key against the payment provider - your export runs the same whether you’re on the free tier or Pro.
A lot of real-world use never touches Pro at all - checking a smaller competitor’s catalog, auditing your own 40-product store, or a one-off spot-check of pricing all sit comfortably inside the 100-product free tier, with no payment step anywhere in the process from start to finish.