It seems like this tutorial use the compiler version is 0.4.x, but now, the newest version is 0.8.x, so I think you should run npm i openzeppelin-solidity@2.0.0 to install.
BTW, you can have a look at some newer tutorials:
It seems like this tutorial use the compiler version is 0.4.x, but now, the newest version is 0.8.x, so I think you should run npm i openzeppelin-solidity@2.0.0 to install.
BTW, you can have a look at some newer tutorials: