When on client side you have such progress bar usually it means that the client is periodically sending requests to the server to get an update of the status. It is called polling mechanism.

If it's the case you should see in your NeoLoad recording few requests with as response a kind of status like a percentage of completion until 100% or any other message/status that tells the client that it is completed.

If you have to mimic that behavior in NeoLoad when running a test, you need to use a while logical loop that includes that polling request. Then extract the status sent by the server and use that result in the condition of your while to drop out of the loop if you get the successful message.

So NeoLoad will send over and over the same  request until the condition is met which is when the server sends a completion status.

So if you have multiple requests, you can remove them and keep only the one that will be used in your while loop action.

I hope it makes sense to you.