Password required for Gitlab clone after setting SSH Key

I am trying to clone a Gitlab repository inside a cluster computer. It asks me for the password for git@gitlab... And once I enter it, it denies the permission.

I have set an SSH Key in Gitlab inside the cluster (I copy pasted the key in authorized-keys file) but it is not being used by Gitlab (I checked it in Gitlab, it says it was never used).

I am getting the following:

[user@eu-login-12-ng ~]$ git clone :user/test.git
Cloning into 'test'...
's password:
Permission denied, please try again.
's password:
Permission denied, please try again.
's password: Connection reset by 129.132.93.72 port 22

If I try clone it in my local computer, it works fine.

What can I do?

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