def METHOD_NAME(ctx, username):
    """Activate a user account."""
    try:
        ctx.obj.user_manager.change_user_activation(username, False)
        click.echo(f"User {username} activated.")
        user = ctx.obj.user_manager.find_user(username)
        if user:
            click.echo("User created:")
            click.echo(f"\t{_user_to_line(user.asDict())}")
    except UnknownUser:
        click.echo(f"User {username} does not exist!", err=True)