SourceTree macOS SSH push error

error message during push:

• check if the ssh agent is running in background:

  eval "$(ssh-agent -s)"

• copy the folling lines into the file: ~/.ssh/config

  Host *
   AddKeysToAgent yes
   UseKeychain yes
   IdentityFile ~/.ssh/id_rsa

• add the ssh key

  ssh-add -K ~/.ssh/id_rsa