I have only made one transfer to Armory (never again)
So, you only need to export the private key of the address you sent bitcoin to.
Check "Address String" when exporting private keys. (It's shown in the image below.)
https://i.imgur.com/pFBEFC8.jpgThen try to find the address you sent bitcoin to. Copy its private key and paste it into electrum.
(The private key is below the address and in front of "PrivBase58".)
All I have for sure is the recipient adress, starts with bc1q (42 characters long)- all keys starts with 5. What am I missing?