Details of webinar rat established (8)
I believe the answer is:
narrates
'details' is the definition.
(I've seen this in another clue)
'of webinar rat established' is the wordplay.
'of' indicates a hidden word.
'NARRATES' is hidden in the letters of 'webinar rat established'.
(Other definitions for narrates that I've seen before include "Tells (a story)" , "provides an account" , "Recites, recounts" .)