How long does upload_url vk api expire?

Question

API

Hello.
I am making a service for uploading graffiti to VK documents. Before executing the script, I get the upload_url using the docs.getMessagesUploadServer method, and the following question arose:

- How long does this upload_url last?
- Is there any limit on the number of uploaded files?

As I understand it, uploading files to one upload_url will be more correct than getting a new one every time. If the first url expires, I will request a new one. But for now, I don't know how to find out when the url won't download files