MQTT M262 certificate – Communities

Object:
Publish data from M262 PLC at a facility to a customer’s MQTT broker.
I have received Server certificate, Client Key and Client certificate from customer as well as mqtt-broker-address.
I am using ME 2.0.

Approach:
I have used the MQTT example from Schneider and modified it so that it does not require an IP address and accepts the server certificate and client certificate.
When I enter the trusted partition of the PLC I am able to place the client server certificate and the client certificate, but client key is not accepted.
There is also no mentioning of this in Schneider Electric MQTT manuals.

Problem:
I do not know where to place the client key and the error message I get in MainVisu is “CertificateNoKey”.

Additional info:
This exact issue will also be an issue for anyone trying to publish to AWS.