There is no hard limit for guests who can join a teams meeting, and there is no Guest user license for Teams. Just forward the teams meeting join link and they can join from browser or teams application installed without signing in by a Microsoft account. Of you wanted to send meeting invite to some external user's email address from team's calendar, you have to type each address in the To list or add all users as guests in your Office 365 tenant. A short video is here to help on that: watch
Maximum number of guest allowed in licensed Microsoft teams

What's the maximum number of guest allowed in a meeting for a licensed single user?
Can the guest be invited by a link without signing up in Microsoft?
3 answers
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Leon Laude 85,131 Reputation points
2020-09-02T09:03:03.04+00:00 Hi,
Guest access is included with all Microsoft 365 Business Standard, Office 365 Enterprise, and Office 365 Education subscriptions. No additional Microsoft 365 or Office 365 license is necessary. Teams doesn't restrict the number of guests you can add. However, the total number of guests that can be added to your tenant may be restricted by the paid features of Azure AD. For more information, see Azure AD B2B collaboration licensing.
Reference:
Guest access in Microsoft Teams----------
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Best regards,
LeonJimmyYang-MSFT 36,221 Reputation points Microsoft Vendor2020-09-03T02:18:46.03+00:00 Hi!
*What's the maximum number of guest allowed in a meeting for a licensed single user?The maximum at the moment is 300 of people in one Teams meeting. This goes regardless of application (web or desktop) or whether the attendees are guests or users.
https://learn.microsoft.com/en-us/microsoftteams/limits-specifications-teams#meetings-and-calls
*Can the guest be invited by a link without signing up in Microsoft?
Sure, you can learn how to join the meeting as a guest via link without signing up from the following article:
https://support.microsoft.com/en-us/office/join-a-meeting-in-teams-1613bb53-f3fa-431e-85a9-d6a91e3468c9#bkmk_link
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