When editing a program and you click "Share or export this program", you see the JavaScript program that is generated from your Python program, and there are instructions on how to use the JavaScript version. One of the ways is to copy the JavaScript code and paste it into a file whose name ends with ".html". Once you have that file on our computer, double-clicking this html file will run the program.
There is now an easier way to create the html file, and the instructions are now available when you click "Share or export this program". You simply click a new link, "Download as HTML", which downloads to your download directory an html file containing the JavaScript code, and which can be executed simply by double-clicking the html file.
Bruce