Hi! As I researched, there is no setting to control Recent Calls on iPhone as it caters call logs on your carrier and the overall calls made on every application throughout your phone.
Hello, I had a similar issue and was able to stop ring central calls from showing in my personal iphone log. However, I just got a new phone and setting has reverted back. There is a way to change this setting as I’ve changed it previously. Will follow up with the results.
Update: Go to your phone settings in the ring central app and scroll all the way to the bottom of the page. You will see integrated calling, toggle that off and ring central calls should no longer appear in your iPhone call log.