I need ongoing help writing powershell scripts

I need assistance creating a powershell script to query my server via REST API. I was able to successfully query using the postmaster app. The application requires a cookie http header with a session id as the value. This session ID is sent by the server when you authenticate using a POST with user credentials in the body. However my powershell script fails when I initiate a GET using the session ID from the post. Below is an attempt I've tried using the invoke-RestMethod. I can successfully submit GET's using the same session ID via the postmaster application which I run from my browser. $ApexID = $(curl -Method Post -ContentType application/json -Body $json -SessionVariable mysession -Uri [login to view URL] | select -expand rawcontent | findstr "Set-Cookie" | % {$_ -replace "^.*:",""} | % {$_ -replace "^.",""} | % {$_ -replace ";.*$",""}) PS C:\Users\z161491> $header3=@{'Cookie'=$apexid} PS C:\Users\z161491> $header3 Name Value ---- ----- Cookie SessionApexId=4aac7041d7df5d97ff0719 PS C:\Users\z161491> Invoke-RestMethod -Method Get -ContentType application/json -headers $header3 -Uri [login to view URL] Invoke-RestMethod : The underlying connection was closed: An unexpected error occurred on a send. At line:1 char:1 + Invoke-RestMethod -Method Get -ContentType application/json -headers ... + ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + CategoryInfo : InvalidOperation: ([login to view URL]:HttpWebRequest) [Invoke-RestMethod], WebException + FullyQualifiedErrorId : WebCmdletWebResponseException,[login to view URL]