I have a raspberry Pi 4 B set up and working has Scratch 1.4 and scratch 2.
Neither of them have an ADD EXTENSION icon at bottom left as shown in beginners guide which uses scratch 3 as an example.page 122 3rd edition
I did down load scratch 3 desktop into my personal laptop and got it to work I see the ADD EXTENSION icon there.
And it puts a short cut to scratch 3 on my desktop on my laptop and it works.
I did it from here
https://scratch.mit.edu/download
However when I try to load it into Pi it acts like it is doing it.
I select "open when done" as it is loading.
It opens scratch 1.4 . Does not open 3
1.4 does not have the ADD EXTESION icon as stated before.
I found scratch 3 in downloads in the Pi and when I open it it opens 1.4 again.
Also it does not put a shortcut for 3 on my desktop on Pi screen
Or show up in programs only 1.4 and 2 show up there.
Any suggestions ?