You need to create a new wallet, but do not delete the existing one. Private key does not move.
Follow the next steps.
Open your wallet, click on the top left menu, then hit the “+ COINS” button in the button and select “Bitcore” from the mind-blowing list of Coinomi’s 86 supported coins and 214 tokens.
A pop-up dialogue will appear, asking if Bitcore should be added. Hit the “ADVANCED SETTINGS” button. In the “Derivation Path” please enter:
M/44H/0H/0H
Please note that the characters before “H” are zeroes and not O’s.
Hint: If you have more than one Bitcoin wallets in your Coinomi and want to claim the equivalent BTX you will have to repeat the above process, replacing each time the last zero with the (zero-based) account index, so for the second wallet this would be M/44H/0H/1H, for the third wallet it would be M/44H/0H/2H, and so forth.
Now click “ADD”.
That’s it! Your BTX wallet is now ready!
After you move BTX from your newly created wallet to the old, you can delete the newly created.
Thank you.
But my BTCs are in different wallet (electrum) and was looking to import the private key of that wallet into Coinomi's BitCore wallet to claim the BTX. I couldn't see a way to do that.
In above steps, It is expected to have the BTC in Coinomi wallet with private keys on the device, and by creating new BitCore wallet and having the private keys there already it would claim the BTX in BitCore wallet, but for someone like me who has different BTC wallet, I couldn't find a way to add the private keys.
read this
https://www.reddit.com/r/NavCoin/comments/6p13k1/how_to_import_a_private_key_from_electrum_wallet/
Thank you Sir,
I was not sure what the sweep would do. That explained it for me.
Once again, Thank you for your help.