Checking lag

It's oracle version 19.21. Is there possible way to get the lag between the primary and DR database in duration with units as seconds/minutes/hours?

All i find is the data dictionary views like v$database,v$standby_log,v$archived_log,v$dataguard_stats tec. But not able to make these query such a way that it will give the results in unit as "seconds" of lag.

The requirement is to use this query in one of the application which will be running it in certain interval before querying data, to ensure the lag is minimal otherwise take some action accordingly on the data fetch queries from teh DR database.

Regards