You seriously can’t manage email aliases for Apple Mail on iOS natively?
@simonwoods depends on what you mean. Adding extra email for domain you use with eg. fastmail? Just add them in settings. Settings > Mail > Account > Account > E-Mail, add new address.
@teisam I mean specifically an alias for my Apple email account. You can view and manage them on the web in an explicit setting but can only do so on iOS if you compose a new message and select the drop-down menu for From.
@simonwoods Ok (I think I understand, but perhaps not). Not a heavy sending/replying with aliases, only for receiving. But if needed, it's easy enough for me (in my book) to add and change the from adress if needed.