Can't access git repository of ubuntu 16.04 LTS from another OS

I am newbie in ubuntu and I don't have much experience in ubuntu. Now, I try to setup git server on ubuntu 16.04 LTS by learing this guide https://www.linux.com/learn/how-run-your-own-git-server.

I want to create git repository on ubuntu and I want to access that git repository from windows 7 as remote. In my windows, I already installed msysgit.

But every times I try to add remote, I got fatal errors like this

fatal: '/Project/code_server' does not appear to be a git repository
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.

I try a lot of way to solve this error more than one days but I can't solve it. I have no idea what I was wrong. So, please guide me. Here is what I've tried.

I want to setup git repository on my ubuntu personal account. So I skip adding a user git step from the above guide.

On my ubuntu personal account, I create git bare repository in the path /opt/lampp/htdocs/Project/code_server by using git init --bare.

(All of the following commands are made by using git bash from windows.)

After that, on my windows laptop, I create ssh key by using git bash like this: ssh-keygen -t rsa without using passphrase. And copy that keys to my ubuntu laptop like this:

$ cat /c/users/my/.ssh/id_rsa.pub | ssh [email protected] "mkdir -p ~/.ssh && cat >> ~/.ssh/authorized_keys"

After that, it shows like this

The authenticity of host '192.168.2.3 (192.168.2.3)' can't be established.
ECDSA key fingerprint is SHA256:CXpg2OJd3KCORAXHu/1zV194iEDElwtRlb8oX6i7X2Q.
Are you sure you want to continue connecting (yes/no)?

so, I said yes and it shows this warning again: Warning: Permanently added '192.168.2.3' (ECDSA) to the list of known hosts. and it ask to write password of ubuntu account and I type the password.

And I change the path to /c/xampp/htdocs/Project/Project-0.3 and make git init and add all code files to version controls and commit.

And then, I try to add remote as shown in below:

my@Pavilion-PC MINGW64 /c/xampp/htdocs/Project/Project-0.3 (master)
$ git remote add origin ssh://[email protected]/Project/code_server

And when I try to push, I got following error.

my@Pavilion-PC MINGW64 /c/xampp/htdocs/Project/Project-0.3 (master)
$ git push origin master
[email protected]'s password:
fatal: '/Attendance/code_server' does not appear to be a git repository
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.

I already set RSAAuthentication yes and PubkeyAuthentication yes and also remove comment # from AuthorizedKeysFile %h/.ssh/authorized_keys.

But the problem still exists and I can't still work with remote git repository of ubuntu from winodws. I'm very appreciate for any helps.