Much suggested to use address starting with 3/bc1 which is called segwit addresses then you can save transaction fees compare using legacy address that starting with 1.
Electrum generates only native SegWit addresses (bc1...) which are still not supported by many popular services. Though one can
trick Electrum into showing nested SegWit addresses (3...) which are backwards compatible.
Saw the trick and I got curious if I can do it for my existing wallet address like to switch from Legacy to Segwit or Segwit to Legacy.
I tried it with my existing Electrum wallet which I have the seed and imported it but it's not working ( I can't get into the navigation which I can select if I want Legacy or Segwit). (as I tried to create a new one: this image is only shown when creating a new wallet):
As I did before creating a fresh wallet from Electrum and generating a new seed, at first they will ask you the seed type if a.) Segwit or b.) Legacy.
I don't know if that trick is working on a new version of Electrum.
EDIT: Found out the answer, I can't do what I want to do.
You can't "convert" your existing Electrum wallet from SegWit to Legacy, you would need to create a completely new wallet (File -> New\Restore -> Standard Wallet -> Create New Seed) and then specify the "Legacy" option when asked what seed type you want to use:
(.....)