Shipping options could not be loaded v4.30

I am using version 4.30 I installed the USPS plugin and I try to simulate a purchase but at the time of shipping it gives me this error: Shipping options could not be loaded.

Thanks.

That means that either none of you selected services were returned by USPS (e.g. 'First Class' may not be returned if weight > 13 oz), or you have some error (like zip code not matching state).  Check the System > Log for error messages.

Thank you very much for taking part of your time to answer me.

I am testing with my own address and all the information is correct, I have already changed to different weights, there is nothing in the logs.

Thanks again.

What selected services do you have in the USPS configuration?

If it's not a services configuration problem, then I would expect there to be something in the system log.  Attempt a checkout, and when you see the "...could not be loaded" message, immediately go to System > Log, and see what's at the top of the list.

I have Priority Mail selected, and I have also tried to do the checkout and in log there is nothing related to that. If you send me your email, I can create you a user and if you can please take a look at it, don't worry even this page is not in production.

I really appreciate your help.

I am having a similar issue with the FedEx Plugin... https://www.nopcommerce.com/en/boards/topic/82851/fedex-plugin-configuration#267125

I also need to configure the plugin for USPS as well so if you will please post when you resolve your issue.

You have a different error and it is related to authentication, make sure that the Key, Account Number, Meter number you have is for production.

Well, it seems that your issue is also " related to authentication".  The USPS plugin is not reporting the error returned.  It just looks for 'packages':

\Plugins\Nop.Plugin.Shipping.USPS\Domain\RateResponse.cs

        public static async Task<RateResponse> LoadAsync(Stream stream, bool isDomestic)
        {
            var response = new RateResponse
            {
                IsDomestic = isDomestic
            };

            try
            {
                var document = await XDocument.LoadAsync(stream, LoadOptions.None, default);
...
               foreach (var package in document?.Root.Elements("Package"))
...

response  =

{<Error>
  <Number>80040B1A</Number>
  <Description>Authorization failure.  Perhaps username and/or password is incorrect.</Description>
  <Source>USPSCOM::DoAuth</Source>
</Error>}

In case anyone is interested, this USPS plugin issue was fixed:
https://github.com/nopSolutions/nopCommerce/issues/4889

However, it was "added [] to the Version 4.40 milestone", so I don't expect that they will update the one for 4.30.  If you need the changes, you will need a developer to make them and recompile the plugin.