How to synchronize data in an ASP.NET site and in the application's local database?

Question

ASP.NET

Good afternoon, colleagues.
I have a C#.NET + SQL Server application running on a local network (a simple CRM with orders). The task is to develop a simple site (preferably: ASP.NET + SQL Server), where the client can see the status of his orders and place new ones. The customer fundamentally does not want to maintain the infrastructure for the site and wants to see it on a third-party hosting.
The question arises: what technology is better to use to synchronize data between two databases?
Thank you.
upd . The question rather relates to at what level and using which technologies it is more correct to synchronize? Options:
1. Data level (synchronization of databases using SQL Server: speed, security)
2. Application level (local application calls the WebAPI of the site)
or other methods.

Answer 1

See Change Data Capture .
And in general, why the requirement in synchronization? Maybe you should look at the same database in both cases?