It’s says as K6 open source tool is not Node.js based.
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Can you share a (sanitized) script so we can have a look and reproduce this? I’m not sure what
crypto module you are importing (webcrypto). If it’s from a nodejs module might not be supported depending in the underlying APIs. We can’t say for sure without the script.
k6 is not NodeJS, nor is it a browser. Packages that rely on APIs provided by NodeJS, for instance the os and fs modules, will not work in k6. The same goes for browser-specific APIs like the window object.