How to change variable in a variable group

[PatrickGrub]

I want to change via C# in Azure Devops in a specific Variable Group a specific variable:
https://docs.microsoft.com/en-us/rest/api/azure/devops/distributedtask/variablegroups?view=azure-devops-rest-5.0

How can I get started? Which VssHttpClientBase do I need? Examples?

[ydbendasan]

You'll need to install Microsoft.TeamFoundation.DistributedTask.WebApi nuget package,
reference Microsoft.TeamFoundation.DistributedTask.WebApi

then you can initialise TaskAgentHttpClient

var devopsConnection = new VssConnection(new Uri(devopsUrl), new VssBasicCredential(string.Empty, devopsToken));
var taskClient = devopsConnection.GetClient<TaskAgentHttpClient>();
var variableGroups = taskClient.GetVariableGroupsAsync(project.Id).Result;

then use methods on these to modify as you desire.

[DavidBergeron-eng]

Not impersonating didn't know.