Why does GitLab ask for a password for a private key if the file is generated without a password?

Question

git

Hello!
I reinstalled the OS (Windows 10 x64), generated a new key, created a $profile$/.ssh/config file with the contents:

# GitLab
Host gitlab.com
RSAAuthentication yes
IdentityFile C:\Users\danforth\Documents\ssh\private.ppk

The key itself was generated without a password. When you try to clone your git repository or push something, it asks for a password. The GitLab help says that if it asks for a password, then something is wrong. How to determine what is wrong?
The config is loading.

$ git push origin master
Enter passphrase for key 'C:\Users\danforth\Documents\ssh\private.ppk': <-- путь к приватному ключу

The key in GitLab itself was accepted successfully. Changed the keys three times and nothing has changed.
What could be the problem?

Answer 1

The problem was that PuTTYGEN generates a file with a private key in its own format, you had to go to PuTTYGEN itself and open the private key, then "Conversion --> Export OpenSSH Key". Saved it and everything worked.