video-js-contrib-eme can't get initializeMediaKeys to work - video.js

Question

In our use case, we need to reuse the same license for multiple sources for different videos, I came across the initializeMediaKeys function, but when called with the following emeOptions:
var emeOptions = {
keySystems : {
"com.widevine.alpha": {
url : myUrl,
audioRobustness: 'SW_SECURE_CRYPTO',
videoRobustness: 'SW_SECURE_CRYPTO'
}
}
}
I've tried several variations of this object as a parameter but I always get a:
instrument.js:109 VIDEOJS: ERROR: (CODE:5 MEDIA_ERR_ENCRYPTED) Unsupported keySystem or supportedConfigurations.
MediaError {code: 5, message: 'Unsupported keySystem or supportedConfigurations.'}
And opening the media error object I get:
MediaError {code: 5, message: 'Unsupported keySystem or supportedConfigurations.'}
code: 5
message: "Unsupported keySystem or supportedConfigurations."
responseContentType: "application/dash+xml"
responseStatus: 200
responseURL:[REDACTED]
token=[REDACTED]
[[Prototype]]: Object
MEDIA_ERR_ABORTED: 1
MEDIA_ERR_CUSTOM: 0
MEDIA_ERR_DECODE: 3
MEDIA_ERR_ENCRYPTED: 5
MEDIA_ERR_NETWORK: 2
MEDIA_ERR_SRC_NOT_SUPPORTED: 4
code: 0
message: ""
status: null
constructor: ƒ MediaError(value)
[[Prototype]]: Object
Could someone help me or give me a hint? Thanks.