I think the README should get some instructions that you actually need to import the OAuth1 library: - Resources > Manage Libraries... - Search for Mb2Vpd5nfD3Pz-_a-39Q4VfxhMjh3Sh48 (see https://developers.google.com/apps-script/migration/oauth-config) - Select latest version and save
I think the README should get some instructions that you actually need to import the OAuth1 library: