How can I set Angular 6 Material sidenav to open right to left from the right side of the screen

If you look to the API tab there is an input directive position for you to define.

position: 'start' | 'end'

The side that the drawer is attached to.

<mat-drawer-container class="example-container">
  <mat-drawer #sideNav mode="side" opened="true" position="end">
    Right drawer
  </mat-drawer>
  <mat-drawer-content>
    Main content
  </mat-drawer-content>
</mat-drawer-container>

DEMO