JavaScript/jQuery PolarChart - legend.title

<dx-polar-chart ... >
    <dxo-legend>
        <dxo-title ... >
            <dxo-font
                color="black">
            </dxo-font>
        </dxo-title>
    </dxo-legend>
</dx-polar-chart>

import { Component } from '@angular/core';
 
@Component({
    selector: 'app-root',
    templateUrl: './app.component.html',
    styleUrls: ['./app.component.css']
})
export class AppComponent {
    // ...
}

import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';
import { AppComponent } from './app.component';
 
import { DxPolarChartModule } from 'devextreme-angular';
 
@NgModule({
    declarations: [
        AppComponent
    ],
    imports: [
        BrowserModule,
        DxPolarChartModule
    ],
    providers: [ ],
    bootstrap: [AppComponent]
})
export class AppModule { }