This is What you need. AppMon can send user visits via POST for into defined URL. You have to create some peace of code that will take it, parse JSON and store in database. Alternatively you can use embedded integration with Elasticsearch if this is fine for client.
Do you say i have to build an end point (API Service) ? Then, i will send the datas to this endpoint, parse here and send to database. Can i do that with .NET Restful Sercice ? What is your suggestion ? ,
Note: We exported the datas to Elasticsearch but your client wants to export to database.
Technology isn't issue here. It can be .NET / PHP / Python / Java or whatever you know and can handle this task. The only thing you have to handle is accepting post requests with JSON payload, parsing JSON and connection with DB. Pick technology that you know best and will not need much work. Remember that if you have many visits, you may have to handle large payloads so code should be well optimized. Another thing is that data related to visits are not flat, so you have to think about database schema. It may need multiple tables with foreign indexes.