my_secure_key in mongo tutorial

I’m following this tutorial https://www.digitalocean.com/community/articles/how-to-securely-configure-a-production-mongodb-server for creating a secure connection to a Mongo database

When I ran these commands # The \s are just to multiline the command and make it more readable ssh \ -L 4321:localhost:27017 \ -i ~/.ssh/my_secure_key \ ssh_user@mongo_db_droplet_host_or_ip

it told me that, regarding this line -i ~/.ssh/my_secure_key , my_secure_key is not accessible. No such file or directory. Am I supposed to replace ‘my_secure_key’ with a key that I get from somewhere?

Thanks for your help