Can not clone repo using SSH key

git clone git@gitlab.com:testgrp61/testproj.git

i created ssh ket and added to SSh KEy in preference…and in my local i created a config file .

i m try to runt he command git clone git@gitlab.com:testgrp61/testproj.git

but it give error

Cloning into ‘testproj’…
kex_exchange_identification: read: Connection reset by peer
Connection reset by 172.65.251.78 port 22
fatal: Could not read from remote repository.

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

please help…