You can use a world downloader mod or just get a client such as cosmic client i know that for a fact has world downloader.
I mean to get them into singleplayer I have tried the world downloader mod but it isn't working. I will try cosmic client thanks
Oh! I know what you mean now. I personally never done that before. I think your best bet is to try Youtube and see what other people have done. Just have to find the right video though and client that works the way you want.
I know that this has been mentioned already, but world download works the best. All you have to do is click "Download world" and load in all the chunks you want to download, then turn it off. It should be in your single player world file named "mineverse" or something like that
There is schematica too. It's just like a world edit schematic using /plot download but you can just choose a specific area instead of downloading the entire plot.
When i get the link from the command, it takes me to the Plot Squared website but it says "File Deleted!"
Oh... please send screenshots in that case. It worked for me in June at least. I don't see why it would be broken now -\_(o.o)_/-