Are you using Bliss launcher?
Lightly touch the screen but don’t tap on any icons.
Swipe from left to right 'til you cannot swipe anymore. You will be on the left-most screen which holds widgets.
There you may see things like SUGGESTIONS; your name, email address, and storage space if using /e/ account; Advanced Privacy widget; weather (maybe).
At the bottom is an ‘Edit’ button. Tap that. From the screen that appears is where you add widgets.
Not on /e/ right now so no screenshots but all is explained here…
[HOWTO] Use the BlissLauncher - eOSWiki / HOWTOs - /e/OS community
Oops, you should have already found that via link provided by @piero .