EVERY TIME I RUN "npm run build" i got this error - reactjs

Question

this is the error shown in terminal when i run "npm run build"
'CI' is not recognized as an internal or external command,
operable program or batch file.
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! reminder#0.1.0 build: `CI= react-scripts build`
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the reminder#0.1.0 build script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.
npm ERR! A complete log of this run can be found in:
this is my package.json
and i think i have error due to "build" : "CI= react-scripts build"
so please review my code and answer it
{
"name": "reminder",
"version": "0.1.0",
"private": true,
"dependencies": {
"#testing-library/jest-dom": "^4.2.4",
"#testing-library/react": "^9.5.0",
"#testing-library/user-event": "^7.2.1",
"react": "^16.13.1",
"react-dom": "^16.13.1",
"react-scripts": "3.4.3"
},
"scripts": {
"start": "react-scripts start",
"build": "CI= react-scripts build",
"test": "react-scripts test",
"eject": "react-scripts eject"
},
"eslintConfig": {
"extends": "react-app"
},
"browserslist": {
"production": [
">0.2%",
"not dead",
"not op_mini all"
],
"development": [
"last 1 chrome version",
"last 1 firefox version",
"last 1 safari version"
]
}
}