Click the green flag and enter the list number of which block you want in the project! Wait a few seconds reload the page, press see inside and it should be in there! If it doesn't work then try inputting the block again. Might not be working right now. I just need to sort out some issues.
Thank you @TimMcCool for scratchattach and CloudRequests. And thank you @Turtsles for inspiration from your original project!
