Why doesn't source ~/.bashrc work from a script?

Question

linux

There is a script to install the software I need.
Install nvm like this:

curl -o- https://raw.githubusercontent.com/creationix/nvm/v0.32.1/install.sh | bash

This patches the ~/.bashrc file.
Now to use nvm to install Node.js , run:

source ~/.bashrc
nvm install v6.8.1

It is written in the script, but the nvm utility is not located.
At the same time, if you wait for the script to execute and manually enter source ~/.bashrc, and then nvm install v6.8.1, then everything works.
I've tried setting a delay sleep 5, but to no avail.
Why might this be happening?

Answer 1

Specify the full path to nvm. Take it from
whereis nvm