but for example in coinomi wallet or trezor wallet.
Link your Trezor to Electrum and follow the steps above.
I didn't see the "spend" when I right clicked, (it's maybe because the balance is 0?
If you right click on an address with funds, you will see the "Spend From This Address" option.
If the address you are trying to spend from has 0.3 BTC made up from multiple inputs, Electrum will automatically use all the inputs in that single address and consolidate all the unspent coins in to a new change address. If you don't want to do this, and want to leave the remaining inputs behind in the same address, then instead of clicking on the "Addresses" tab click instead on the "Coins" tab, and in the same way described choose only the individual inputs you wish to spend.