cv.imwrite is not a fuction error

edit

My version of opencv I am using w/require statement is https://docs.opencv.org/3.4.1/opencv.js from open cv web site.

My problem is that it doesn't seem to support imwrite statements (or at least I can't find imwrite when it's searched)

The result is I can't execute a basic imwrite statement in OpenCV.js?

Succh as cv.imwrite('testimg.png', mat);

provides the basic javascript error below:

Uncaught TypeError: cv.imwrite is not a function at HTMLImageElement.img_input.onload (index.2.html:76)

So I just want to confirm that 'https://docs.opencv.org/3.4.1/opencv.js' does not include imwrite, imdecode, etc

Thx