Property assets is not allowed in angular.json projectType is library

Question

i am getting property not allowed error in my angular.json file.

i am using @angular/cli 15 to build library for my project.

i tried using different builders its not working.

"architect": {
    "build": {
      "builder": "@angular-devkit/build-angular:ng-packagr",
      "options": {
        "project": "projects/nad-frontend-modules/ng-package.json",
        "assets":[
          "src/assets",
          "src/styles"
        ]

      },
      "configurations": {
        "production": {
          "tsConfig": "projects/nad-frontend-modules/tsconfig.lib.prod.json"
        },
        "development": {
          "tsConfig": "projects/nad-frontend-modules/tsconfig.lib.json"
        }
      },
      "defaultConfiguration": "production"
    },
    "test": {
      "builder": "@angular-devkit/build-angular:karma",
      "options": {
        "tsConfig": "projects/nad-frontend-modules/tsconfig.spec.json",
        "polyfills": [
          "zone.js",
          "zone.js/testing"
        ]
      }
    }
  }