A challenging cryptic with too many slang terms and modernisms for my liking. Spare a thought for the old fogeys, please!
3D "Frying pan" - isn't that a definition by example? If so, it has no indicator.
2D That is a term that I have never heard - is it essentially a US term?
19A Very clever clue!
13D Another term that I am unfamiliar with - I must have had a sheltered upbringing! Following research, I would have said "pita" is the name of the bread and "pita pocket" the name of a sandwich.
21D Horrid clue! Surely one is asking permission?
24D General Knox is not very well-known in the UK!
23A Horrid clue! I can't see how to parse it.
20D Another "modernism" that I have never heard before. Following research I don't see "webinar" as a class.
15A I can't parse this, even knowing the answer.