Using self-signed certificates is not recommended due to the configuration required on the runner to support them. If you do need to use a self-signed certificate, you will need to configure the certificate on each runner.
The correct steps for configuring the self-signed certificate will depend on how it is generated, and the platforms and technologies used on your runners (which may validate the certificate in different ways).
Some tips for successfully configuring self-signed certificates are included below. These steps can be taken before or after registering the runner.