I have check the tutorial on how to use RBF in Electrum: https://bitcoinelectrum.com/frequently-asked-questions/#my-bitcoin-transaction-is-not-confirming-what-can-i-do
But i could not find any button, menu entry or a setting like that in my Electrum-btc-x86_64.AppImage on Linux. My app language is not english.
Is it because I have selected outputs on a Coins tab or what to try?