How to create dynamic Google map connected with SQL server database

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C#

ASP.NET

SQL

server

I am creating an online Customer Service and Support System, for Agents, using SQL Server 2016 and ASP.NET, C#

I have to create a map showing red flags on the locations where the customers have issues with the machines provided.
When clicking the flag, more information will appear. That information should be extracted from SQL database, from more than 3 tables.

Also, every time an agent is updating an issue or add a new one, the details on the map should change automatically.

What are your suggestions?

What I have tried:

I have tried adding new attributes into Customer table, Latitude and Longitude. But then I got stuck with how will those cells be filled in automatically after the agent insert the address and postcode.
Then I just created a google map with API key, and used just the Postcode. Then exported Customer details to Excel file. The problem is that I need to connect the SQL database with the Excel spreadsheet in such way that Excel spreadsheet would update at the same time database is updated.

To be mentioned, the Excel spreadsheet should gather details out of 4 tables from the SQL database.

I am not an advanced developer, but I am keen to learn. Maybe the question is "easy peasy" for most of you :) Please bare with me.