When fitting a 3/4" male elbow fitting into a shower valve, whats the best way of making sure the elbow fitting finishes at the required angle ?

When I turn it fully home so that the flange seats then it ends up pointing the wrong way !

Have tried wrapping ptfe tape but doesn't really work as not convinced the seal would be adequate for the pumped supply unless it also mechanically seats fully home in some fashion.

Should I be using some kind of fibre washer as a spacer, or is there a better way ?

Many thanks

Couldn't source these locally today.

Is there any other suitable way I could go about it, or is this the standard approach ?

Thks