With your purchase at IFT website, you will be paying for a subscription for materials to help you pay for the current year or next years (e.g. 2023 or 2024) exam.  This depends upon when you plan to sit the CFA exam.  After your exam year, the materials are out of date because each year CFA Institute changes the curriculum. 

Note that the items such as Notes and slides, which are provided in PDF format you can download and keep. 

Once the subscription valid till date arrives you will lose your access.  You will find this policy is common with the CFA approved prep providers.