Cannot generate new theme

[thomasbritton]

Current Behavior

As per the documentation to create a theme with the following command:

nx generate @trafilea/nx-shopify:theme theme-name

It returns me the following error message:

Cannot set property 'theme-name' of undefined

Expected Behavior

Expect a theme to be generated as per the documentation

Steps to Reproduce

Follow the installation steps from the documentation site and make a new theme

This issue may not be prioritized if details are not provided to help us reproduce the issue.

Failure Logs

Error message returned in console:

Cannot set property 'theme-name' of undefined

Environment

I'm using Ubuntu under WSL on WIndows 10,
Installed Nx with npm.

NX Report

Node : 14.16.1
OS : linux x64
npm : 6.14.12

nx : Not Found
@nrwl/angular : Not Found
@nrwl/cli : 13.1.3
@nrwl/cypress : Not Found
@nrwl/devkit : 13.1.3
@nrwl/eslint-plugin-nx : Not Found
@nrwl/express : Not Found
@nrwl/jest : 12.0.8
@nrwl/linter : 13.1.3
@nrwl/nest : Not Found
@nrwl/next : Not Found
@nrwl/node : Not Found
@nrwl/nx-cloud : Not Found
@nrwl/react : Not Found
@nrwl/schematics : Not Found
@nrwl/tao : 13.1.3
@nrwl/web : Not Found
@nrwl/workspace : 13.1.3
@nrwl/storybook : Not Found
@nrwl/gatsby : Not Found
typescript : 4.3.5