Office Scripts are indeed available for Excel on the web, but they are not available for Outlook on the web (OWA). Unfortunately this means you cannot directly transfer your VBA script to Office Scripts in OWA.
While Microsoft has been making efforts to bring more automation capabilities to OWA, such as through add-ins and the new Outlook REST API, it's important to note that these are different technologies and may not offer the same level of customization and automation as VBA or Office Scripts in Excel. But Microsoft regularly updates its products and services. I recommend checking the latest Microsoft documentation or announcements for any updates on the availability of Office Scripts for Outlook on the web. Microsoft's official website, developer documentation, or community forums are good places to stay updated on any developments in this area.