Custom App - Login Fail

[BMSUser]

Hi,

I have created a custom app to integrate Shopify with POS database locally..

It is complete functional app where Login , Upload of Products download of Orders etc. was working.

Today, when I try to run the app I am getting login error with API credentials.

Here are the steps I take to create APP and generate keys etc.

bmsWave.myShopify.com
App Development -> WaveShopifyApp ,  Custom App Name I am using and providing 

API Key and Secret key. I am providing two keys 
{"errors":"[API] Invalid API key or access token (unrecognized login or wrong password)"}
Original String : "https://bmswave.myshopify.com/admin/api/2022-04/products/6678918856784.json"

This was all working few months ago and now it has suddenly stopped.

Can someone from Shopify support help us out?

Thanks!

[m8th · Accepted solution]

Maybe the "X-Shopify-Access-Token" header is missing in your query.

It's hard to give help to such a problem without any sample code.

Would recommend to test a query via cURL or a client like Insomnia.

Good luck

[BMSUser]

Yes I was missing the access token key in header section.

Recently Shopify has added token based authentication method. My code works perfect now.

Here is my code for those who may be in the same situation

restSharpRequest.AddHeader("content-type", "application/json");
restSharpRequest.AddHeader("Accept", "application/json");
restSharpRequest.AddHeader("X - Shopify - Access - Token", "XXXXXXXXXXXXXXX");

"XXXXXXXXXXXX" here is Admin API key I generated from Custom app section.