Settings app not appearing

I am not able to locate Settings in Ubuntu 20.04 LTS. I have been using Ubuntu for the last 1 year but it is not visible to me now. Don't know what is happening. Can someone help me with this?

First you need to check whether you accidentally uninstalled your system settings app.

Try running:

whereis gnome-control-center

If the result is showing a path, then your settings app package is not removed and you can open it from terminal by executing:

gnome-control-center

Then the app may be accidentally removed somehow from your shell menu, which you can be fixed using a menu editor like menulibre. You may refer to this answer to know more about it: How to edit the Applications Menu in GNOME 3?

Else, if whereis didn't return a path and returned something like this:

gnome-control-center:

you somehow got the package removed from your system, so do reinstall it using apt:

sudo apt update && sudo apt install gnome-control-center -y

Hope this will solve your issue.