To enable transient retries in dotnet core, put the following into the startup process. In this case, it went into a WorkerService, so the code is in the Program.cs file.

services.AddHttpClient("AnyClientName")
    .AddTransientHttpErrorPolicy(x =>
        x.WaitAndRetryAsync(
            Backoff.DecorrelatedJitterBackoffV2(medianFirstRetryDelay: TimeSpan.FromSeconds(1),
            retryCount: 5), onRetryAsync: async (outcome, span, retryAttempt, context) => {
                Log.Logger.Warning("Delaying for {delay}ms, then making retry {retry}.", 
                    span.TotalMilliseconds, retryAttempt);
            })
    );

The above code will try for 5 times using a backoff logic that adds some random time to it so that the backoff logic will not add another problem with an api. This also logs when it does a retry. The above code is using Serilog, so your logging logic may be different.

The NuGet packages installed to enable this are:
Polly.Contrib.WaitAndRetry
Microsoft.Extensions.Http.Polly
Serilog.Extensions.Hosting
Serilog

Here is a link that explains the retry backoff logic:
https://github.com/Polly-Contrib/Polly.Contrib.WaitAndRetry