How to add an ssh-tunnelled remote to an existing repo?

I have a local repo on my laptop which already has a remote called origin. Apart from my laptop and origin, there is a third machine called remote1 which I want to add as another remote to my local repo. What I do on my laptop is

    git remote add remote1
    git remote set-url remote1 ssh://sshUser@remote1Address:path/to/.git

But when doing so, the command git push remote1 branchName gives

  ssh: connect to host remote1Address port 22: Connection timed out.

Accessing remote1 through ssh is possible only through a jump proxy. Port 22 being closed is the main reason behind using a jump proxy in this case; Here is my .ssh/config

Host jumpProxy
    Hostname jumpProxyAddress
    User jumpUser

Host remote1
    Hostname remote1Address
    User sshUser
    ProxyJump jumpUser@jumpProxyAddress

so I guess the source of the problem is that the jump proxy is not called at all, that is, .ssh/config is not read at all. What solution do you suggest?

I see two things wrong with your git remote set-url statement:

1. You've defined a specific hostname for remote1 in ~/.ssh/config with the proxy and user details, but you aren't using it.
2. The URL format is incorrect: if you're going to use ssh:// then there should be a slash between the user@host details and the repository path (not a colon).

You should be able to fix both with a single statement: git remote set-url remote1 ssh://remote1/path/to/.git. (Note that there's no user@ there; it's defined in your ~/.ssh/config.)