Check out example codes for "No directive found with exportAs 'matAutocomplete'". It will help you in understanding the concepts better.

Code Example 1

import { MatAutocompleteModule, MatFormFieldModule } from '@angular/material';

@NgModule({
    imports: [
        ....
        MatAutocompleteModule, 
        MatFormFieldModule,
        ....
    ],
    ....
})
export class AppModule { }

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