I’m not sure that they can generate a keypress event “initially” (I think you may be right that you can’t, but it won’t surprise me when you know that there is some extreme case when this is possible).
However, I do not think that they would have a problem with simple execution element.onkeypress()directly. If the bot can determine that it needs to press a key to advance, then what actually comes down to calling the handler method of a specific event, and the bot can do the latter. He can create his own fake Event object, also containing the key code, and then pass this and / or set it to window.event.
, , . , , , , , . // ..
, , , , "" . , click, Javascript .