Deployment on heroku failed - node.js

Question

I want to deploy my exiting project on heroku, but it gives me an error.
structure of my file:
___instagram
__backend
_controllers
_images
_middleware
_models
_node_modules
_routes
_utiles
.gitignore
app.js
package-lock.json
package.json
Procfile
__ui
...
commands:
E:\Coding\projects\instagram>git add .
E:\Coding\projects\instagram>git commit -m "update controllers"
[master 086d891] update controllers
1 file changed, 1 insertion(+), 1 deletion(-)
E:\Coding\projects\instagram>cd backend
E:\Coding\projects\instagram\backend>git push -f heroku master
after the last command (git push -f heroku master) i got this error:
E:\Coding\projects\instagram\backend>git push -f heroku master
Enumerating objects: 16, done.
Counting objects: 100% (16/16), done.
Delta compression using up to 4 threads
Compressing objects: 100% (9/9), done.
Writing objects: 100% (10/10), 956 bytes | 956.00 KiB/s, done.
Total 10 (delta 4), reused 0 (delta 0), pack-reused 0
remote: Compressing source files... done.
remote: Building source:
remote:
remote: -----> Building on the Heroku-20 stack
remote: -----> Using buildpack: heroku/nodejs
remote: -----> App not compatible with buildpack: https://buildpack-registry.s3.amazonaws.com/buildpacks/heroku/nodejs.tgz
remote:
remote: ! ERROR: Application not supported by 'heroku/nodejs' buildpack
remote: !
remote: ! The 'heroku/nodejs' buildpack is set on this application, but was
remote: ! unable to detect a Node.js codebase.
remote: ! A Node.js app on Heroku requires a 'package.json' at the root of
remote: ! the directory structure.
remote: !
remote: ! If you are trying to deploy a Node.js application, ensure that this
remote: ! file is present at the top level directory. This directory has the
remote: ! following files:
remote: !
remote: ! backend/
remote: ! ui/
remote: !
remote: ! If you are trying to deploy an application written in another
remote: ! language, you need to change the list of buildpacks set on your
remote: ! Heroku app using the 'heroku buildpacks' command.
remote: !
remote: ! For more information, refer to the following documentation:
remote: ! https://devcenter.heroku.com/articles/buildpacks
remote: ! https://devcenter.heroku.com/articles/nodejs-support#activation
remote:
remote:
remote: More info: https://devcenter.heroku.com/articles/buildpacks#detection-failure
remote:
remote: ! Push failed
remote: Verifying deploy...
remote:
remote: ! Push rejected to ins-app-clone.
remote:
To https://git.heroku.com/ins-app-clone.git
! [remote rejected] master -> master (pre-receive hook declined)
error: failed to push some refs to 'https://git.heroku.com/ins-app-clone.git'

Answer 1

Heroku buildpack looks at the top-level (root) for package.json.
The solution here is to use git sub-trees. I too was facing this issue where I had a Monorepo MERN codebase in which I wanted to deploy my server using Heroku and client via Vercel.
I have written a blog post regarding this, I'm sure you'll get an idea regarding a solution to this.
Link to Blog Post