Hi @rahulbharti3333
Okta does not have a Nativescript SDK available currently.
You can submit a feature request to Okta Ideas, more information about how to use Okta Ideas found here: Okta Help Center (Lightning).
Once ideas are submitted, other Okta admins will have the ability to vote on them to help our Product team prioritize requests. Additionally, you will be able to monitor the potential for future enhancements there.
Does Okta provide the accurate expiration time of the refresh token to frontend clients? It seems that Okta consistently sends the expiration time of the refresh token as the same as the access token, regardless of the library used
No, the refresh token expiration time will not be returned in the /token response from Okta. The only expires_at value that will be returned is for the Access Token, as noted in our documentation here.
The only way to validate a Refresh Token would be to send it to the Introspection endpoint or to send it to the Token endpoint to request new tokens when the original set of ID/Access tokens has expired.