VSTS build running locally - error: "Microsoft Internet Explorer. Enhanced Security Configuration" - powershell

Question

I'm running Windows 10 and making a script to handle/start VSTS builds.
Sample call (overriding properties for testing):
$env:SYSTEM_TEAMFOUNDATIONCOLLECTIONURI = "https://mytenancy.visualstudio.com/"
$env:SYSTEM_TEAMPROJECTID = "Project1"
$env:SYSTEM_DEFINITIONID = 5
#$env:SYSTEM_ACCESSTOKEN = "mytoken" - uncomment when running locally
$url = "$($env:SYSTEM_TEAMFOUNDATIONCOLLECTIONURI)$env:SYSTEM_TEAMPROJECTID/_apis/build/definitions/$($env:SYSTEM_DEFINITIONID)?api-version=2.0"
Write-Host "URL: $url"
$definition = Invoke-RestMethod -Uri $url -Headers #{
Authorization = "Bearer $env:SYSTEM_ACCESSTOKEN"
}
Write-Host "Definition = $($definition | ConvertTo-Json -Depth 100)"
"Authenticated"
This script works fine on the server, but if I uncomment the $env:SYSTEM_ACCESSTOKEN and run locally, I get the following error:
Microsoft Internet Explorer\u0026#39;s Enhanced Security Configuration
is currently enabled on your environment. This enhanced level of
security prevents our web integration experiences from displaying or
performing correctly. To continue with your operation please disable
this configuration or contact your administrator.
I'm running Windows 10.
I've tried many things, including:
Turning off as much security as possible in Internet Options.
Fresh Token
Converting the token to a secure string
Converting to a Base64 string as detailed in the answer to this post
How can I authenticate locally?
EDIT (following accepted answer)
The accepted answer solved the problem. I think the two key points here were:
The correct encoding in conversion to Base64
Changing authentication from Bearer to Basic when running in this way (locally).
Final code:
$user = "[username]"
$accessToken="[token]"
$base64AuthInfo = [Convert]::ToBase64String([Text.Encoding]::ASCII.GetBytes(("{0}:{1}" -f $user,$accessToken)))
$env:SYSTEM_TEAMFOUNDATIONCOLLECTIONURI = "https://mytenancy.visualstudio.com/"
$env:SYSTEM_TEAMPROJECTID = "Project1"
$checkBuildUrl = "$($env:SYSTEM_TEAMFOUNDATIONCOLLECTIONURI)$($env:SYSTEM_TEAMPROJECTID)/_apis/build/builds/$($requestedBuildId)?api-version=2.0"
$buildStatus = Invoke-RestMethod -Uri $checkBuildUrl -Headers #{Authorization=("Basic {0}" -f $base64AuthInfo)}

Answer 1

Create a new access token and refer to this code to call the REST API through PowerShell:
$user = "[anything]"
$accessToken="[access token]"
$base64AuthInfo = [Convert]::ToBase64String([Text.Encoding]::ASCII.GetBytes(("{0}:{1}" -f $user,$accessToken)))
...
Invoke-RestMethod -Uri $uri -Method Post -ContentType "application/json" -Headers #{Authorization=("Basic {0}" -f $base64AuthInfo)} -Body $bodyJson
Regarding enhanced security, there is a similar issue:
Enhanced Security Error while Visual Studio Team Services Rest API