NullInjectorError using ngs-mask in angular

Question

I want to create input field in angular, it is customized:

<cs-input [field]="inputname" formControlName="inputname"></cs-input>

the .ts file has declaration:

reactiveFormGroup = this.fb.group({
    fname: ['', Validators.required],
    sname: '',
    selectData: '',
    inputname: ''
    })

and inputField is:

  inputname: InputField = {
uniqueFormKey: "inputname",
type: InputTypeEnum.text,
id: "inputname"

}

and i get error:

    ERROR NullInjectorError: R3InjectorError(AppModule)[InjectionToken ngx-mask config -> InjectionToken ngx-mask config -> InjectionToken ngx-mask config]: 
  NullInjectorError: No provider for InjectionToken ngx-mask config!

In angular app.module.ts i have declarations:

    imports: [
    BrowserModule,
    FormsModule,
    ReactiveFormsModule,
    NgxMaskModule.forRoot(),
    NgbModule,
  ],

and i've exported config:

export const config: InjectionToken<any> = new InjectionToken('ngxmask config');

Can you help me? What i'm ding wrong?