I mean the "from" address, that Electrum generates for the use of sending.
There is no such thing as a "from address" in bitcoin. Addresses are used to receive bitcoins, not to send them.
If you are using the wallet correctly, then you should be generating a new address for every transaction that you receive. Think of an address like an invoice number. You generate a new one everytime you want to receive a payment from someone. Then you take a note of who you gave the address to, and what the address was for. That way, when you receive a payment at the address, you will be able to identify who sent it and what they are paying for.
When you later spend those bitcoins, the payments that were received get spent. It is possible to look back in the blockchain and see what address that payment was received at, and some people and wallets mistakenly call the address that the payment was previously received at a "sending address", but this is a dangerous misunderstanding about how bitcoin works and will lead to confusion and complications in the future.