Perhaps you can do it while registering your root with RouterModule. You can pass a second object with property useHash:true like the below:
import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { AppComponent } from './app.component';
import { ROUTES } from './app.routes';
@NgModule({
declarations: [AppComponent],
imports: [BrowserModule],
RouterModule.forRoot(ROUTES ,{ useHash: true }),],
providers: [],
bootstrap: [AppComponent],
})
export class AppModule {}