Runner to accept self signed certificate

It seems that Runner does not like self signed certificates:

Registering runner... failed [0;m [31;1mrunner[0;m=waug24ur [31;1mstatus[0;m=couldn't execute POST against https://gitlab.domain.com/api/v4/runners: Post https://gitlab.domain.com/api/v4/runners: x509: certificate signed by unknown authority

Seems that there is a doc to fix that https://docs.gitlab.com/runner/configuration/tls-self-signed.html but i am still not sure how to approach this in Kubernetes environment. At which point can i copy over the certificate?

Thx, Leo