How remove a "use of undeclared identifier: FIRDynamicLink"?

We are following the dynamic instructions for Firebase here, which lists just one import needed "@import Firebase" - yet when we get to their line

FIRDynamicLink *dynamicLink = [[FIRDynamicLinks dynamicLinks] dynamicLinkFromCustomSchemeURL:url];

if (dynamicLink) { ...

...XCode gives an undeclared identifier for FIRDynamicLink. Unlike some of the other modules like "import FirebaseAnalytics" - there doesn't seem to be another library dedicated to Dynamic Links.

The pod content is: pod "Firebase/DynamicLinks"

What is the trick to get this to compile?