//You have to add { useHash: true } in your router module

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 {}

Use HashLocation strategy.

Add to top level module

import { HashLocationStrategy, LocationStrategy } from '@angular/common';

providers: [{provide: LocationStrategy, useClass: HashLocationStrategy}],