The below sample code will make an HTTP call using powershell with Authorization headers. However when you run the code it will fail.
$token =  az account get-access-token | ConvertFrom-Json
$mytoken =  $token.accesstoken
$headers = @{ Authorization = "Bearer $token.accesstoken" }
echo $headers
Invoke-RestMethod -Method Get -Uri "https://management.azure.com/subscriptions/xxxxx/resourceGroups/resource-group/providers/Microsoft.Sql/servers/sql-server?api-version=2020-11-01-preview" -Headers $headers -UseBasicParsing

This is an error occuring on powershell as the $token.accesstoken is not correctly parsed. In order to resolve either use a new variable and assign the value on it ($mytoken)
$headers = @{ Authorization = "Bearer $mytoken" }
		