Cannot declaremodule in an NgModule as it’s not a part of the current compilation Angular

When importing modules in Angular it should be placed under the imports array not declarations.

declarations: [
    AppComponent,
    // ReactiveFormsModule---remove from declarations and add in import because its is imported
    // FormsModule`enter code here`---remove from declarations and add in import
],
imports: [
    ReactiveFormsModule,
    FormsModule
]