According to Google the PKCE support is not an option! In 2025 Expo recommends a library with a Paywall.

[RemiZlatinis]

This discussion focuses on the lack of PKCE (Proof Key for Code Exchange) support in the
react-native-google-signin library. We'll explore the implications of this limitation, discuss alternative solutions, and examine the Expo recommendation for a paid library in light of this issue.

[vonovak]

Hello and thanks for asking,
It would be nice to know how you arrived at your PKCE conclusion.

Thank you 🙂