ESI SSO: Invalid Request, some parameters are either missing or invalid

[Slippu]

I’m creating a new app using Angular cli (because I apparently hate myself), and whenever I try to authenticate via SSO, I get the response:

error: “invalid_request” error_description: “Some parameters are either missing or invalid”

Which sounds like a simple enough error. But this is the URL I’m sending;

https://login.eveonline.com/oauth/authorize/?response_type=code&redirect_url=http%3A%2F%2Flocalhost%3A4200%2Fauth-callback&client_id={client_id}&scope=publicData%20esi-location.read_location.v1%20esi-characters.read_chat_channels.v1%20esi-location.read_online.v1

And as far as I can see and as far as I’ve compared it to other login url’s, I can’t find where it’s failing.

Any help would be massively appreciated.

Update / Edit: I have also attempted to use the OAauth2 method (/v2/oauth/authorize) and provided a state parameter, and that gives me the helpful message of:

Message: An error has occurred.

[Blacksmoke16]

Id read over https://docs.esi.evetech.net/docs/sso/web_based_sso_flow.html#overview-of-oauth-20-flow-for-web-based-applications and make sure you’re not missing anything. Whether that be query params, headers, etc.

[Slippu]

That’s what I originally thought, but I’ve scoured that documentation.

response_type = code
redirect_uri = matches the application, url is encoded
client_id = matches the application
scope = encoded, have even tried just with publicData to avoid spacing issues with no dice.
state = provided a unique string identifier

And yet still nothing. Also regarding the headers, I haven’t even gotten that far yet as to sending the correct headers back to the servers yet.