Discourse Integration app don’t redirect me back to Nextcloud and don’t work

[LosHunterros]

Nextcloud version (eg, 20.0.5) : 29.0.0
Operating system and version (eg, Ubuntu 20.04) : Ubuntu 20.04.6 LTS
Apache or nginx version (eg, Apache 2.4.25) : Apache/2.4.41
PHP version (eg, 7.4) : 8.2

I am trying to connect Nextcloud with Discourse by Discourse Integration app. This is my configuration in Discourse:

And in Nextcloud:

When i click on ‘Connect to Discourse’ i am redirected to Discourse:

But if i click ‘Authorize’ i get an error, i am not redirected back to Nextcloud and i don’t have any changes in Nextcloud

Error:
Failed to launch 'web+nextclouddiscourse://auth-redirect?payload=h0zAd7muVMb9BOgGy7h9yAHjlfo%2F4H3uW%2BerBcTqjtuI0cAE2i8%2F758rjIJJ%0AZICHZUdkEd2yokRhJZBdY1XuHMdwhfH%2Bixsq%2FJjwp9BI2ptxAY6ZqffmMShm%0APY8dcr2GFCnrJ9Cvbeu1EqbyQ0M0jarTBkphJ4nOeoTkuKNbQJhDkbmDwhup%0A%2Benz%2Bkyn43ddT4GulLXBtl0ZhzbfR0kkkwbnGJZoGWsLBXmWr%2FyltCve4dEI%0AlQZKWexlnasa%2B0hx6gq7C9mx9fT5viVLBBG2RlGGTACI7zppxXAbnmKTebw%2B%0AoRVYJXIAFnboHsr0WbsI65ixJLmj0KccvCBaBssAsA%3D%3D%0A
’ because the scheme does not have a registered handler.

What am i doing wrong?

P.S.
If that’s important i have Discourse SSO app installed and working properly.

[keithkhl]

I have exactly the same problem, just with different language.
I've also played around with api key, but nothing worked so far.

[andrey18106]

@LosHunterros Hello, have you configured the Application (should be prompted like described on settings page) in your browser to handle such links to redirect back to correct instance URL? Have you tried another browser?

[LosHunterros]

You're right. Currently i am able to do this only in Firefox. Other browsers don't show any prompt so i don't know how to accept this - i don't know - custom protocol? But Firefox handle everything fine.

[andrey18106]

You're right. Currently i am able to do this only in Firefox. Other browsers don't show any prompt so i don't know how to accept this - i don't know - custom protocol? But Firefox handle everything fine.

There is registerProtocolHandler used to do so, and it is not supported only in Safari, additionally it works only in secure context (https). https://developer.mozilla.org/en-US/docs/Web/API/Navigator/registerProtocolHandler#browser_compatibility

If you are using chromium based browser, could you please double check if enabling chrome://settings/handlers -> Allow sites to ask to become default handlers for protocols resolves the problem and if there are already registered entries?

Anyway there will be a button to trigger protocol registration manually in the next update.

[LosHunterros]

It looks like this:

2025-02-11.22-01-45.mp4

[andrey18106]

It looks like this:
2025-02-11.22-01-45.mp4

Weird, looks like it is only Opera browser issue (can't confirm locally in Chrome or Firefox). I thought you just don't receive prompt to register custom protocol handler, which is the case for me in Chrome (and it needs a manual trigger to prompt registration), therefore browser don't have a redirect handler. Can you confirm it in another Chromium-based browser?

[LosHunterros]

I think when i posted this issue about year ago i didn't receive a prompt in Chrome. But now i do get it (even before last update) and after accept everything works fine.

In Opera, after last update, i am redirected to Chrom. So it looks like - with this workaround - it also works fine.