Have you tried this? -->
https://www.woorank.com/Alexa is known for this job but if that doesn't suit your budget, they have a free trial which you can use. But if that still doesn't work, post the websites here that you want to know the traffic and let's wait for someone to the rescue. Maybe he has paid for a plan there or have some other ways to determine the traffic of such websites.
It was very helpful to me, I will use it in the future, thank you very much
data traffic are mostly confidentail when it comes to knowing it, as it doesn't only logs the number of visitors, but also what are the devices used and even the information of a user. And it is commonly being used only by a website owner or a company's data and network heads. Hence, knowing do costs a lot as you must also have permission to the owner. Those online traffic detectors are mostly fake and only uses algorithm of how is it popular in SEOs with no proper traffic leeching involved.
I only need to know the number of visits, no need for customer information, so I need free services