Kube-apiserver use selfsigned cert


I’m new with rancher 2.0. From the last week, I’ve build a HA cluster with 3 compute node.
The admin gui use my own ssl cert, the deployment is smooth and everythinks work.

But I would like to setup the AutoDevOps feature with Gitlab.
And I encounter some blocking error. Let me describe the error.

I’ve converted the base64 cert autorithy to pem format, copied it to gitlab kubernetes ca cert.
Do the same with the token, everythink seem OK.
But I got a message telling me to check the CA cert and the token.

If I try manually to access the API_url:6443, I’ve got an ssl error “NET:ERR_CERT_AUTHORITY_INVALID”
When I check the ssl cert ->
CN : kube-apiserver
Authority CN: kube-ca

How can a set my own ssl to avoid this error, or how can I bypass this error to enable the access from GitLab?

Thanks you in advance.
Best regards.