When we are running our Jmeter test we are testing 100-1000 users, but how close is that to actual 1000 users on our website? Is there ways to ensure that our script is very close to 1000 users? Is there tools or ways to better ensure that I can tell my company that that our website can handle 1000 users?

We are receiving below error in JMeter version 5.6.2
WARNING: Supplied DOM uses namespaces, but is not created as namespace-aware

I am trying to do replay jmeter script recorded for CSRF-protected website. I did correlation , but its throwing 401 unauthorized error and message reads You need to enable javascript“. I do not see anything like Cookie: csrftoken attributes in request header or response body in view results tree to proceed further .