Empty string refresh_token

[tequdev]

I am trying to create a Xumm Provider in NextAuth, the Next.js authentication library.
https://github.com/nextauthjs/next-auth

An error occurs if the refresh_token is an empty string ("") in the oauth4webapi check used inside NextAuth.
https://github.com/panva/oauth4webapi/blob/87585b522a4a996bc9d42d42d00d8faa759cd1c5/src/index.ts#L1973-L1979

Please consider refresh_token for this service.
https://github.com/XRPL-Labs/XUMM-OAuth2-OpenID-Provider/search?q=refresh_token

I am not familiar with OpenID and do not know if refresh_token is an required field even if it is an empty string.