Enter the portal and go out to the health sauna in the forest city. You can follow these steps:

1, after entering the adventure island game, come to the city in the forest first.

2. Find the taxi npc on the map, talk to him and choose the healthy road.

3. After reaching the road to health, continue the dialogue with npc and choose to enter the next map.

After entering the next map, go straight to the right and walk to the end of the road.

You will see a portal at the end, and you can leave the health sauna after entering the portal.