First convert the chart by pressing "7" and click on the type of engine that supports the chart. It will ask you to put the chart in. Open the ORIGINAL .json file in Notepad. Copy EVERYTHING in there. Paste it. Then it'll ask for the number of keys. For most charts, there's 4 keys: Left, Down, Up, and Right. so either leave it blank or put in 4 for most charts. If you're converting a chart like God Eater, then enter 9 keys. It'll convert the chart for you. Then export the chart and put it in a different engine or use this one. Then delete the "DELETE ME" sprite.
Main engine by @SquigglyTuff Chart and camera converter by @SpideyPlaysMC