Invalid integration key in request credentials

[mpunderw]

I've tried multiple things. Deleting and recreating the app. I've tried the sKey encrypted and in plaintext. I've verified that TLS 1.2 is enabled.

40102 ; Invalid integration key in request credentials
At C:\WINDOWS\system32\WindowsPowerShell\v1.0\Modules\Duo\Duo.psm1:31 char:5
throw $formatError

CategoryInfo : OperationStopped: (:) [], FormatException
FullyQualifiedErrorId : 40102 ; Invalid integration key in request credentials