multi signature – How do you sign an unsigned transaction using Electrum in a multisig setup?

I am experimenting with multisig in testNet between Electrum and Caravan by Unchained Capital. I created a 2-of-2 multisig in Electrum with BIP 39 seeds.

I then created a watch-only wallet in Caravan with master public keys. The issues occur when I try to make a transaction in Caravan. For each of the 2 private keys, I need to sign the raw transaction that Caravan provides, but I don’t know how to perform that action in Electrum to create the signature. Is it possible to do this on Electrum or do I need some other software?
Carvan transaction