How to update to latest Ubuntu?

[mahesh]

When i try:

sudo apt-get update
sudo apt-get upgrade
sudo apt-get dist-upgrade

I get:
E: The repository 'https://deb.etcher.io stable Release' does not have a Release file.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure( manpage for repository creation and user configuration details.


And I don't know how to get out of this box! LOL
BIOS Aptio Setup Utility - 2012 American Megatrends Ver 2.15.1226
Intel® Core™ i5-3210M CPU @ 2.50GHz × 4
Intel® Ivybridge Mobile 16 GiB ram, 120 GB HD, 64-bit
Ubuntu 20.04 LTS / Win 10 ( Someday LOL )