For enterprise RDA, you'll be using an identity provider. You can either use Kerberos, ADFS, or our own Security Token Service (STS). If your organization is already using Kerberos or ADFS, then you can configure that identity provider in your common config as a means of authenticating users to your Robot Manager instance.
If you do not already use either of those, then you can install and use the STS. I would suggest getting assistance here from either Pega or one of our partners as the initial setup is best done with someone with experience.
Once you have it setup, you can apply the same setting to Runtime and Studio in your CommonConfig. For Studio though, we typically use basic authentication where you have a user name and password to your Pega instance as several of the services accessed during development only work with basic authentication. These are mostly used for RPA though, so you probably would not encounter this strictly using RDA.