I have a completed MS Access software engine for a specific task and want to develop a UI for it.
There are some hacky ways to do this with an old version of Access using SharePoint. I tried this a while back and found it pretty limiting. MS treated it like a red-headed step child and eventually discontinued it. So I don't know if this really works anymore.
Access was designed way before the dynamic internet and really only works on a local machine or a local network. If you wanted to make the data available on a WAN or the internet, you were supposed to use SQL Server for the data (and you could still use Access as the front end.)
And that is my advice. Port the Access to SQL Server on Azure. Don't make a Frankenstein monster trying to mix the file based Access and the Internet based Retool. There are tools out there to help you do the migration like Migrate Access Databases to SQL Server - Azure SQL Database - SQL Server | Microsoft Docs and Access on Azure SQL - How to create an online Access application using Azure SQL and ODBC - YouTube