I'm experiencing difficulties

What difficulties?

I'm encountering errors

What errors?

Unfortunately, we can't help without any information on the issue.

unfortunately I don't have much knowledge about the problem, but when I make a request using POST next Request in the server log this comes up “INFO: - ‘GET /compare-audio/ HTTP/1.1’ 400 Bad Request” locally it returns correct “INFO: - ‘POST /compare-audio/ HTTP/1.1’ 200 OK” on the front end side I'm using the same api and the same address.

Have a look at this docs section -

https://docs.railway.app/guides/fixing-common-errors#post-requests-turn-into-get-requests

unfortunately this is not the case i tested it on an https server https://projecta.top/game/1 and the same error is being returned i also checked how the request is being sent and it is correct there is no redirect

INFO: Application startup complete.

INFO: 127.0.0.1:59662 - “POST /compare-audio/ HTTP/1.1” 200 OK

INFO: 100.64.0.3:26984 - "GET /compare-audio/ HTTP/1.1" 400 Bad Request

Please give me an endpoint that I could query to see this behaviour for myself.

the closest thing to an endpoint I can send you is this link https://projecta.top/game/1 it records your microphone and sends it to the api which sends it to this api on the railway on the client side I can assure you that everything is working the problem is between my api: https://justpaste.it/e6cgu and the server on the railway generous-recreation-production-e712.up.railway.app both sides are public my api https://projecta.top/api/audio but I believe you won't be able to access it.

Given that this is an application level error and not a platform error -- I would need a simple example endpoint that showcases the issue otherwise I unfortunately won't be able to help here.

i believe it's an incompatibility between nextrequest and your side i'll try to host the api on vercel

This is not a platform issue, this would be a miss-configuration with your app, or due to how you are calling the domain.

Could you please check the value of process.env.NEXT_PUBLIC_COMPARE_AUDIO_IA_URL?
If the URL starts with http://, you should update it to https:// as this could solve your problem.

    const response = await fetch(`${process.env.NEXT_PUBLIC_COMPARE_AUDIO_IA_URL}/compare-audio/`, {

      method: 'POST',

      body: formData,

    });