I now found the text just not a picture.
"Hi,
We at IKEA would like to inform you about a change to our TRÅDFRI Gateway. We are very happy to see your interest in our gateway and have seen that you are using the CoAP interface. We consider the CoAP interface as our internal interface not developed for third party usage and therefore we do not offer any technical support for this usage. However that does not mean that we want to hinder your work in any way.
There are some security improvements in a soon coming update that we would like to inform you about since it will break your implementation. Technically the improvement is that the TRÅDFRI Gateway will start using DTLS Identities which you will need to handle in your application.
Please use the Following string to connect to the TRÅDFRI Gateway and create a new DTLS Identity.
coap-client -m post -u “Client_identity” -k “SECURITY_CODE” -e ‘{“9090”:“IDENTITY”}’ “coaps://IP_ADDRESS:5684/15011/9063”
SECURITY_CODE is what is labelled on the Gateway label, IDENTITY is any string that is representing the connection.
You will then get back a PRE_SHARED_KEY that can be use in all traffic after that.
coap-client -m get -u “IDENTITY” -k “PRE_SHARED_KEY” “coaps://IP_ADDRESS:5684/15001”
We also would like to request that the SECURITY_CODE that is printed on the gateway is never stored permanently in your application.
Best regards
IKEA of Sweden Trådfri team"