Oauth2: Support PKCE

[clocklear]

Hello!

The new OAuth 2.0 features introduced in #1654 are awesome, but they don't support PKCE flows. Adding this functionality is critical to the usability of OAuth 2.0 features within Bruno.

https://oauth.net/2/pkce/
https://blog.postman.com/pkce-oauth-how-to/

Thanks!

(This is for Bruno v1.10.0)

[sjw1066]

Agreed - PKCE is the way for mobile applications, so support is really important.

[elovelan]

PKCE is working great! Can this be closed?

[clocklear]

Yep! Have used it myself multiple times; forgot this was open tbh.