Hello Артём Аймалетдинов,
Welcome to Microsoft Q&A forum.
Before we proceed, may I know what the issue is when you try to buy and download the apps?
Please note that this is a user-to-user support forum. Moderators, contributors including external Microsoft employees cannot directly intervene in Microsoft product features or access back-end systems. Our role is limited to providing technical guidance on reported issues, requests, or ideas. I'll do my best to help you make the purchase by yourself.
If you need support regarding your account, please contact Microsoft Support for further insight.
Thank you for your understanding. I'm waiting for your reply.