How to access information from the user's VKontakte page using a bot?

Question

API

Good day.
I decided to write a bot in which you need to access information from the user's page, his communities and posts on the wall.
Well, or rather, the user himself presses the allow button at some point, on a standard pop-up window about allowing access to information, and the server, in turn, processes this information.
Can you please tell me the best way to implement this?
I have two options:
Write a site with authorization through social networks, where the user logs in and clicks the allow button. After that, this information is transmitted to the server, processed in the bot itself by id, the user who entered it becomes active.
Or write an application for VKontakte (in the social network itself), where such functionality would be performed.
After all, as far as I understand, bots can only interact and send information from the community to which they are connected and by themselves cannot receive additional information about the user.
Maybe there are easier ways or maybe my methods also do not fit?