Pretty much just like you did with coinomi but use the wallets in this article...
https://steemit.com/bitcoin/@tiberiu/how-i-claimed-sbtc-super-bitcoin-from-my-paper-wallet

I just imported my private keys from electrum (after moving to a new offline wallet of course)

Easy peasy and you get access to superbitcoin (didn't even know that was a thing lol) too. I used gate.io to sell as they're one of the only ones you can actually deposit to.