How to use the fortnitepy.ClientPartyMember function in fortnitepy

async def copy(ctx: fortnitepy.ext.commands.Context, *, epic_username: Union[str, None] = None) -> None:
    if epic_username is None:
        member = client.party.members.get(ctx.author.id)
    else:
        user = await client.fetch_profile(epic_username)
        member = client.party.members.get(user.id)

    await client.party.me.edit(
        functools.partial(
            fortnitepy.ClientPartyMember.set_outfit,
            asset=member.outfit,
            variants=member.outfit_variants
        ),
        functools.partial(
            fortnitepy.ClientPartyMember.set_backpack,
            asset=member.backpack,
            variants=member.backpack_variants
        ),
        functools.partial(
            fortnitepy.ClientPartyMember.set_pickaxe,
            asset=member.pickaxe,
            variants=member.pickaxe_variants
        ),
        functools.partial(
            fortnitepy.ClientPartyMember.set_banner,
            icon=member.banner[0],

user = await client.fetch_profile(epic_username)
        member = client.party.members.get(user.id)

    await client.party.me.edit(
        functools.partial(
            fortnitepy.ClientPartyMember.set_outfit,
            asset=member.outfit,
            variants=member.outfit_variants
        ),
        functools.partial(
            fortnitepy.ClientPartyMember.set_backpack,
            asset=member.backpack,
            variants=member.backpack_variants
        ),
        functools.partial(
            fortnitepy.ClientPartyMember.set_pickaxe,
            asset=member.pickaxe,
            variants=member.pickaxe_variants
        ),
        functools.partial(
            fortnitepy.ClientPartyMember.set_banner,
            icon=member.banner[0],
            color=member.banner[1],
            season_level=member.banner[2]
        ),
        functools.partial(
            fortnitepy.ClientPartyMember.set_battlepass_info,
            has_purchased=True,
            level=member.battlepass_info[1]
        )
    )

print('Main client ready. Launching sub-accounts...')

        clients = []
        device_auths = get_device_auth_details()
        for email, password in credentials.items():
            client = fortnitepy.Client(
                auth=fortnitepy.AdvancedAuth(
                    email=email,
                    password=password,
                    prompt_authorization_code=True,
                    delete_existing_device_auths=True,
                    **device_auths.get(email, {})
                ),
                default_party_member_config=fortnitepy.DefaultPartyMemberConfig(
                    meta=(
                        functools.partial(fortnitepy.ClientPartyMember.set_outfit, 'CID_175_Athena_Commando_M_Celestial'), # galaxy skin
                    )
                )
            )

            # register events here
            client.add_event_handler('device_auth_generate', self.event_sub_device_auth_generate)
            client.add_event_handler('friend_request', self.event_sub_friend_request)
            client.add_event_handler('party_member_join', self.event_sub_party_member_join)

            clients.append(client)

        try:
            await fortnitepy.start_multiple(
                clients,
                ready_callback=self.event_sub_ready,
                all_ready_callback=lambda: print('All sub clients ready')

async def lobby(ctx: fortnitepy.ext.commands.Context) -> None:
    if client.default_party_member_config.cls == fortnitepy.JustChattingClientPartyMember:
        client.default_party_member_config.cls = fortnitepy.ClientPartyMember

        party_id = client.party.id
        await client.party.me.leave()

        await ctx.send('Removed state of Just Chattin\'. Now attempting to rejoin party.')

        try:
            await client.join_to_party(party_id)
        except fortnitepy.errors.Forbidden:
            await ctx.send('Failed to join back as party is set to private.')
        except fortnitepy.errors.NotFound:
            await ctx.send('Party not found, are you sure Fortnite is open?')

    await client.party.me.clear_in_match()

    await ctx.send('Set state to the pre-game lobby.')

clients = []
device_auths = get_device_auth_details()
for email, password in credentials.items():
    authentication = fortnitepy.AdvancedAuth(
        email=email,
        password=password,
        prompt_authorization_code=True,
        delete_existing_device_auths=True,
        **device_auths.get(email, {})
    )

    client = fortnitepy.Client(
        auth=authentication,
        default_party_member_config=fortnitepy.DefaultPartyMemberConfig(
            meta=(
                functools.partial(fortnitepy.ClientPartyMember.set_outfit, 'CID_175_Athena_Commando_M_Celestial'), # galaxy skin
            )
        )
    )

    # register events here
    client.add_event_handler('device_auth_generate', event_sub_device_auth_generate)
    client.add_event_handler('friend_request', event_sub_friend_request)
    client.add_event_handler('party_member_join', event_sub_party_member_join)

    clients.append(client)

fortnitepy.run_multiple(
    clients,
    ready_callback=event_sub_ready,
    all_ready_callback=lambda: print('All clients ready')
)