Teams - Guest access will be automatically enabled for all tenants on 8 Feb 2021
Microsoft is making changes to the default guest setting in Microsoft Teams. Effective February 8, 2021, they will enable guest access in Microsoft Teams by default for all customers who have not configured this setting. (MC228482)
This setting will change
At present, guest access is disabled, but if you want guest access for Microsoft Teams to remain disabled for your organisation, you should disable it here.
Browsefor this to: https://admin.teams.microsoft.com/company-wide-settings/guest-configuration
Add guests in Microsoft Teams?
In this blog you can read how to add guests or external persons in Microsoft Teams.
How to get started with a Microsoft Teams implementation.
Enable remote access to collaborate in Teams
Basic guide to Microsoft Teams
Block downloading of O365 files to an unknown device
Teams Disable guest access for one Team without PowerShell