To create a conversation using this, you will need to work on a PC with a text editor installed, such as Notepad (Windows) or TextEdit (Mac). An IDE such as VSCode that handles HTML is also fine.
Fill out the conversation you want to create and then hit the 'Generate Code' button. A preview of your creation will be shown in the other window.
The code will show in the white box below. Hit Control / Command + A to select all of the code and copy it.
Paste the code into a plain text file and save it as 'filename.html' using your chosen text editor. (You can call the file whatever you want as long as it ends in .html and it will open in your browser)
You can then upload the file to somewhere like Neocities to share it online.