Lambda Function Version Upgrade (16.x to 20.x)

Go to AWS console ---> Lambda ---> Functions

Select the function here, for which we want to upgrade the version ---> Actions ---> View details

In details page, go down.. will get "Runtime Settings"

Under "Runtime Settings".. click on "Edit".. It will open new page

On this page.. will get option to select the version from dropdown list

So, change runtime version from 16.x to 20.x and click on "Save"

Once we click save, it will save and get back us on details page

Now on details page.. click "Action" ---> select "Publish new version" ---> click "Publish"

It will again get back us to details page.. here then click "Update code"

Then we can check under "Runtime settings" newly upgraded version.