After searching a lot on the web and with the community help I figured out how to configure 2 differents bitbuckets account on my Mac - MacOS Monterey.
Suppose that you have 2 bitbucket accounts witch usernames are username1 and username12.
- Open the terminal and create 2 ssh file2 for both usernames:
ssh-keygen -f ~/.ssh/username1-Bitbucket
ssh-keygen -f ~/.ssh/username2-Bitbucket
- Start ssh-agent:
eval $(ssh-agent)
- Create or edit the ~/.ssh/config file:
Create:
touch ~/.ssh/config
open ~/.ssh/config
Edit:
open ~/.ssh/config
The ~/.ssh/config file should look like this:
Host username1-Bitbucket
    HostName bitbucket.org
    User username1
    IdentityFile ~/.ssh/username1-Bitbucket
Host username2-Bitbucket
    HostName bitbucket.org
    User username2
    IdentityFile ~/.ssh/username2-Bitbucket
Host *
    UseKeychain yes
    AddKeysToAgent yes
    PreferredAuthentications publickey
    IdentityFile ~/.ssh/username1-Bitbucket
    IdentityFile ~/.ssh/username2-Bitbucket
    IdentitiesOnly yes
    PreferredAuthentications keyboard-interactive,password
- Add the keys to the ssh-agent:
ssh-add --apple-use-keychain ~/.ssh/username1-Bitbucket
ssh-add --apple-use-keychain ~/.ssh/username2-Bitbucket
- Copy the ssh key and add it to your bitbuckets accounts. See link:
pbcopy < ~/.ssh/username1-Bitbucket.pub
pbcopy < ~/.ssh/username1-Bitbucket.pub
- Check if connection to bitbucket succeeded (At least one) in order to add Bitbucket as a known hosts:
ssh -T git@bitbucket.org
- Clone your repositories using ssh and cd on the terminal to the repository folder. 
- Check the reposiroties remote url: 
git remote -v
You'll get information like this one:
git@bitbucket.org:companyUserName/repositoryName.git
- Change the repositories remote url:
git remote set-url origin username1@username1-Bitbucket:username1/repositoryName.git
git remote set-url origin username2@username2-Bitbucket:username2/repositoryName.git
So we changed git@bitbucket.org:companyUserName/repositoryName.git to username1@username1-Bitbucket:username1/repositoryName.git
git -> username1 or username2, the username of the accounts.
bitbucket -> username1-Bitbucket or username2-Bitbucket, the host alias of the config file.
companyUserName -> It's the username of the account that holds the repository, in our case the repositories are owned by username1 or username2.
repositoryName -> The name of the repository.
- Test your connection on both repositories creating a new branch and trying to push it:
git checkout -b newBranch
git push origin newBranch
If everything works correctly on both repositories, you are done!
Hope that this solution works for every Mac user.
That's all folk!