Hi @FedeBocc,
You could for example store the messages and the selected people in a SharePoint list.
Below is an example. Hopefully that is similar to what you are looking for?
1. Using a list like below. Where the Title is storing the message and a Date column is used to determine what the message for today is. In the SelectedPersons column (Person or Group) you can select on or more persons.

2. The flow uses a daily recurrence.
3. The Get Items filters for list items which have a Date of today. Use the following Filter query:
Date eq '@{utcNow('yyyy/MM/dd')}'
4. The Apply to Each loops through the SelectedPersons field value of the first list item it found
outputs('Get_items')?['body/value'][0]['SelectedPersons']
5. The Create a Chat uses the Email of the person for the Members to Add field
item()?['Email']
6. The Create a Chat uses the title of the first list item it found for the Title field (which would be the message of the chat)
outputs('Get_items')?['body/value'][0]['Title']
