The web version is included in pretty much every M365 SKU:
A: Following is a complete list of the Microsoft 365 commercial plans that will include the Visio web app: Microsoft 365 Business Basic, Microsoft 365 Business Standard, Microsoft 365 Business Premium, Microsoft 365 Apps for business, Office 365 E1, Office 365 E3, Office 365 E5, Office 365 F3, Microsoft 365 F3, Microsoft 365 E3, Microsoft 365 E5, Microsoft 365 Apps for enterprise, Office 365 A1, Office 365 A3, Office 365 A5, Microsoft 365 A1, Microsoft 365 A3, and Microsoft 365 A5.