How to determine from which request a specific client came from SEO?

Question

Search Engine Optimization

Hello everyone,
I used one online website builder a couple of months ago, and the bottom line is that in this designer, when an application was received, along with all the data that the user filled in, the search engine (Yandex, Google, mail) and the key request that went a user from the search and left a request.
It is important to note that a metric was attached to the site, the metric was attached through the interface of the site builder, and perhaps this matters to determine the request.
I tried to search in Google Yandex how to implement such an idea, but I did not find a working method.
Can you tell me if this is feasible at all, maybe there is already a ready-made working solution?