This page shows two ways of sharing your Google Calendar, along with the user interface differences. To learn more about how to embed Google Calendar in Notion, please read this article.
Google Calendars have a Public URL that can be shared and look like the calendar below.
Each time this calendar loads, it will open up to the monthly view.
https://calendar.google.com/calendar/embed?src=amaverify%40gmail.com&ctz=America%2FLos_Angeles
Plus allows you to take a Snapshot of any Google Calendar view (e.g., daily, agenda, weekly, monthly) and easily share it or embed it in other tools.
https://app.plusdocs.com/plus/snapshot/cl8v5hbb4264609lcm6vbx63y
Interested in trying out Plus? Sign up for free at www.plusdocs.com.