Need help with npm and eslint

Hi,

I’m new to npm & co.
While I try to install my clean new macOS, I get the following error.
I do not understand the problem and so can not fix it.
Can somebody help me with that?

npm ERR! code ERESOLVE
npm ERR! ERESOLVE unable to resolve dependency tree
npm ERR! 
npm ERR! While resolving: health@0.4.0
npm ERR! Found: eslint@5.16.0
npm ERR! node_modules/eslint
npm ERR!   dev eslint@"^5.16.0" from the root project
npm ERR!   peer eslint@"^5.16.0" from eslint-config-nextcloud@0.1.1
npm ERR!   node_modules/eslint-config-nextcloud
npm ERR!     dev eslint-config-nextcloud@"0.1.1" from the root project
npm ERR!   1 more (babel-eslint)
npm ERR! 
npm ERR! Could not resolve dependency:
npm ERR! peer eslint@">=6.2.2" from eslint-config-standard@14.1.1
npm ERR! node_modules/eslint-config-standard
npm ERR!   dev eslint-config-standard@"^14.1.1" from the root project
npm ERR! 
npm ERR! Fix the upstream dependency conflict, or retry
npm ERR! this command with --force, or --legacy-peer-deps
npm ERR! to accept an incorrect (and potentially broken) dependency resolution.
npm ERR! 
npm ERR! See /Users/flost/.npm/eresolve-report.txt for a full report.

npm ERR! A complete log of this run can be found in:
npm ERR!     /Users/flost/.npm/_logs/2021-02-18T19_18_05_038Z-debug.log
undefined
npm ERR! code 1
npm ERR! path /Applications/MAMP/htdocs/nextcloud/apps/health
npm ERR! command failed
npm ERR! command sh -c NODE_ENV=production webpack --progress --hide-modules --config webpack.prod.js

npm ERR! A complete log of this run can be found in:
npm ERR!     /Users/flost/.npm/_logs/2021-02-18T19_18_05_112Z-debug.log
make[1]: *** [npm] Error 1
make: *** [build] Error 2

The repository for the app is here: GitHub - datenangebot/health: Nextcloud health app

Cheers