Error with backend canister

Hello All,
I used the motoko playGround and my backend is working well in playground.
Motoko Playground URL

But somehow with same code my project backend is getting failed. Getting below error.
WARN: Building canisters before generate for Motoko
Also backend url generated as below.


Error Image as mentioned below.

Without trying to recreate your error (but, I did try it on Motoko playground), I think you built the canisters before generating the candid interface file.The warning message says something to that. And, the 400 (Bad Request) would be because it doesn’t have an interface file to tell it how to access the canister.
Generating a new candid file prior to deploying fixes this.