I'm getting 400 status code, when trying to update my records. How to update records in C# API?

I'm getting 400 status code, when trying to update my records. How to update records in C# API?

Hello here, I have a problem with updating the field in Account records. How can I do it in C#?

My code:





I was trying to use request.Ids = ids, but Ids should be long, but an example, it's showing that I have to use List<string>. So how can I update just one field? I need to update Visiting_address for all my accounts. 

I found also this way, but it's still not working for me:
https://www.zoho.com/crm/developer/docs/csharp-sdk/module-samples.html?src=mass_update_records

How can I just make mass update for all my accounts and it's only for one field?