What is my "gitlab instance URL"?

I want to push to my repo without having to enter my username and password for every interaction.
In order to do this, I’ve added my ssh public key to my account details.

I’m not going through the documentation in order to set up passwordless push.
I’m currently going through this document:

The documents describe how to verify connection:
“Open a terminal and run this command, replacing gitlab.example.com with your GitLab instance URL:”

I have no idea what a “gitlab instance URL” is, or how to find one.
I can’t find a description that makes this phrase meaningful.

What exactly is my “gitlab instance URL”?

Search the forums before posting when people have already asked this question many times already: