There you go. You’re using node 15, which has npm 7 by default. You’re hitting this issue:
As the issue says, you can workaround the bug with npm i --legacy-peer-deps.
(I also reported the example to the github issue)
So… if you don’t need new feature, then probably better to stick with LTS nodejs and “latest” npm - which is node 14 / npm 6.
