Uhm... that's pretty much baked into the design of TIST, and one of many reasons it's generally considered a poor quality game. I'm going to assume "hitting button of openbor pc engine twice" is mistranslated and what you really mean is an auto fire. That can be scripted as part of a project in production, but there is no option to retroactively apply it to an existing game. That would be the engine forcing a design aspect onto creators and that's not what we do.
If you want auto fire you're going to have to modify the game or use a control system add-on. Sorry.