mdb-simple-chart undefined

I'm am trying to show mdb-simple-chart like this:HTML page:

<mdb-simple-chart [percent]="80" [barColor]="circleColor" [animate]="{duration: 2000, enabled: true}"></mdb-simple-chart>
<h5>
<span class="badge red accent-2 p-2">Change <mdb-icon fas icon="{{ changeIcon }}" 
class="ml-1"></mdb-icon></span>
<button type="button" class="btn btn-info btn-sm p-2 waves-effect waves-light" placement="top"
mdbTooltip="Percentage change compared to the same period in the past" mdbWavesEffect>
<mdb-icon fas icon="question"></mdb-icon>
</button>
</h5>

This is my module file:

imports: [
    CommonModule,
    RouterModule,
    FormsModule,
   MDBBootstrapModulesPro.forRoot(),
    ChartSimpleModule,

** this is the error i'm getting

ERROR ReferenceError: EasyPieChart is not defined at EasyPieChartComponent.push../node_modules/ng-uikit-pro-standard/fesm5/ng-uikit-pro-standard.js.EasyPieChartComponent.ngOnInit (ng-uikit-pro-standard.js:19017)

how do i fix it so i can use mdb-simple-chart and mdb-icon and mdb-tooltip?