URL Types configuration

Open the workspace of your project and go to Target > Info > Url Types.

You should add two Url Types, one with the value of the CLIENT_ID as URL Scheme and the other with the value of the REVERSED_CLIENT_ID of the downloaded file.

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
    <key>CLIENT_ID</key>
    <string>xxxxxxxxxxxxx.apps.googleusercontent.com</string>
    <key>REVERSED_CLIENT_ID</key>
    <string>com.googleusercontent.apps.xxxxxxxxxxxxx</string>
    <key>PLIST_VERSION</key>
    <string>1</string>
    <key>BUNDLE_ID</key>
    <string>com.serg-ios.MyVocabulary</string>
</dict>
</plist>

Build the project, everything should work fine 🤞