Get access token OAuth 2.0 - Unfortunately, we can't open page
I am having troubles to get my access token with OAuth 2.0 - Implicit Grant. When first trying to get my access token, I immediately got "Unfortunately, we can't open page" but reading in another thread, I was able to get to the login page by adding in preferences for "Internal Browser" - "Trust the self-signed certificate".
However, when logging in correctly into the browser, I end up in the "Unfortunately, we can't open page" just after.
Anyone can help me to deblock this? Would be great.