You can invite up to 50 friends in the Pokémon Sleep app. To see how you can properly build up your friends list, you can take a look at this tutorial from Seeking Tech.
1. For the first step, you need to open Pokémon Sleep on your smartphone if you haven’t done so already.
2. Tap the screen in the Tap to Start screen to log into your account.
3. In the Let’s Get Sleeping screen, you should find the Friends option on the bottom right side.
4. In the Research Community menu, tap the human torso icon with the plus sign on the upper right side.
5. You should now be in the Add Friend/Your Information menu.
On this screen, you will be shown your researcher ID that you can send to your friend. There is also a QR code that your friend can scan on their phone in order to add you to their friends list.
6. In the same Add Friend/Your Information menu, you can also add a friend by using any of the following options:
- Scan 2D code
- Enter a Researcher ID
- Search via Faceboook
7. Once you add a friend to your list, return to the aforementioned Research Community menu to view your friends list.