Import deck in MTG Arena structure and see if the cards are on the list.
Import from CSV
If you have a Collection in CSV format like MTG Goldfish, you your collection here and see it.
The data shown after import is not stored anywhere except your device and your session.
Card,Set ID,Set Name,Quantity,Foil,Variation Abandoned Sarcophagus,HOU,Hour of Devastation,3,regular,"" "Aegar, the Freezing Flame",KHM,Kaldheim,1,regular,showcase Adventurous Impulse,STA,Strixhaven: Mystical Archive,1,foil,""
Import from MTG Goldfish
Go to Tools > My Collection > Export > Request CSV > Refresh page and Right click on the > Download button and copy the content.