how to get the access right?

[SeekPoint]

mldl@mldlUB1604:~/ub16_prj/STQA$ git submodule update --init --recursive
Submodule 'question_answering/bi-att-flow' (git@github.com:agent-jay/bi-att-flow.git) registered for path 'question_answering/bi-att-flow'
Submodule 'question_generation/nqg_learningtoask' (git@github.com:agent-jay/nqg.git) registered for path 'question_generation/nqg_learningtoask'
Cloning into 'question_answering/bi-att-flow'...
Warning: Permanently added the RSA host key for IP address '13.250.177.223' to the list of known hosts.
Permission denied (publickey).
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.
fatal: clone of 'git@github.com:agent-jay/bi-att-flow.git' into submodule path 'question_answering/bi-att-flow' failed
mldl@mldlUB1604:~/ub16_prj/STQA$ sudo git submodule update --init --recursive
[sudo] password for mldl:
Cloning into 'question_answering/bi-att-flow'...
Warning: Permanently added the RSA host key for IP address '13.250.177.223' to the list of known hosts.
Permission denied (publickey).
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.
fatal: clone of 'git@github.com:agent-jay/bi-att-flow.git' into submodule path 'question_answering/bi-att-flow' failed
mldl@mldlUB1604:~/ub16_prj/STQA$