User identification when navigating between sites?

Question

User identification

Good time of the day. I have a question regarding the identification of users on the Internet. Let's say there is a site that contains links to surveys. When you click on a survey, that site redirects to another site that already hosts the survey itself. That is, a person enters the survey and at the same time he is assigned some kind of identifier during the transition. Since when you click on the link again, it says that the survey has already been completed. You can copy the address of the survey in the address bar and when changing the ip address, clearing cookies and cache, you can go to this survey, pass it, but you cannot receive a reward, since it is tied to the old identifier. It turns out the reward has already been received by the user. But the site lets you take a survey, because it considers that this is already a different user. The question is how to find out your new ID and link it to the survey. That is, as I understand it, you can change something in the address bar so that it defines it as a new user and sends the reward there. If there are knowledgeable people tell me please, I will be grateful.