Creating a chat functionality using Slack API

I am having a problem understanding this problem as I have not had much - if any - interaction with Slack API. The problem is listed as follows:

We need to integrate a chat function allowing users to talk to trainers. Slack API is going to be used for this function.

Now, say - UI and Auth are both already implemented. The following is not implemented as part of the network layer yet :

1 - Send/read messages

2 - List/create groups and conversations (channels)

3 - Get a list of the users in the team

4 - Update current status from online, away, etc...

The question is:

How would you design the network layer for this service? Why did you choose such a design?

I am really not understanding the way this is worded and any assistance would be of much appreciation and cordiality here.

This is what my understanding is use Slack API pre-built-in functions:

1 - To get and post messages.

2 - To list and create new channels

3 - To get the list of the team users

4 - To update user status

The problem is this does not sound like a design as this latter would require a database and such.