Local notebooks have been removed.
This is a ridiculous and infuriating decision that has caused me to move away from Evernote.
You might want to look at using Joplin, which was designed as an open-source Evernote alternative. I strongly recommend using Open Source software, as this avoids exactly what Evernote has just done: holding your personal data hostage in a proprietary format and forcing you to pay in order to use it again.
To get your local Evernote data back, download the Legacy version from here: https://help.evernote.com/hc/en-us/articles/360052560314-Install-an-older-version-of-Evernote . Then select all notes, export them, and import them into Joplin.