ssh: connect to host github.com port 22: Connection timed out

The reason could be the firewall modification as you are under a network.(In which case they may deliberately block some ports)
To double check if this is the reason ... do

ssh -T [email protected]

this should timeout. If that's the case use http protocol instead of ssh this way
just change your url in the config file to http.
Here is how :-

git config --local -e

change entry of

 url = [email protected]:username/repo.git

to

url = https://github.com/username/repo.git

For my case none of the suggested solutions worked so I tried to fix it myself and I got it resolved.

For me I am getting this error on my AWS EC2 UBUNTU instance, what I did to resolve it was to edit the ssh config (or add it if it does not exist).

sudo nano ~/.ssh/config

And I added the following

Host github.com
 Hostname ssh.github.com
 Port 443

Then, run the command ssh -T [email protected] to confirm if the issue is fixed.

According to this

Sometimes, firewalls refuse to allow SSH connections entirely. If using HTTPS cloning with credential caching is not an option, you can attempt to clone using an SSH connection made over the HTTPS port. Most firewall rules should allow this, but proxy servers may interfere

Hopefully this helps anyone else who's having the same issue I did.

inside the .ssh folder Create "config" file

Host github.com
User git
Hostname ssh.github.com
PreferredAuthentications publickey
IdentityFile ~/.ssh/id_rsa
Port 443

Host gitlab.com
Hostname altssh.gitlab.com
User git
Port 443
PreferredAuthentications publickey
IdentityFile ~/.ssh/id_rsa