Error while adding netlify cms

[castasint]

I am trying to add netlify cms plugin(using npm install netlify-cms-app gatsby-plugin-netlify-cms but I am getting the below error. I'm following this post https://www.gatsbyjs.com/docs/how-to/sourcing-data/sourcing-from-netlify-cms/. Any advice on how it can be fixed?

Package.JSON:

[LekoArts]

Try running the installation with the --legacy-peer-deps flag as suggested in the message