An example of git ssh configuration for using different keys with the same host

.ssh config

# An example of git ssh configuration for using different keys with the same host
# You should put this file in ~/.ssh/config
# And change IdentityFile to the paths to your keys
# After that, you can use the keys like that:
# git clone ssh://github_key1/user/repo1.git
# git clone ssh://github_key2/user/repo2.git

Host github_key1
    HostName github.com
    User git
    IdentityFile ~/my-ssh-keys/private-key1
    IdentitiesOnly yes
    
Host github_key2
    HostName github.com
    User git
    IdentityFile ~/my-ssh-keys/private-key2
    IdentitiesOnly yes
    
# etc.