I want to push some software to ‘dev’ branch. Software was developed to another computer with Windows and currently I have reinitialize git repository from scratch on Linux machine and want to push my job to company repository and add my patch to previous dev branch

 git init
 git branch -M dev
 git remote add origin https://github.com/<company>/<repository>.git
 git add .
 git commit -m "first commit"
 git pull --rebase origin dev git@gitserv:<company>/<repository>.git

last command don’t working and I don’t understanding my trouble. Firstly I have Github key what looks as SHA256:CUxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Secondary I have “Personal access tokens (classic)” what we usually setting under point “Developer setting” and what look as ghp_xxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Third, I have this ~/ssh/config

  Host gitserv
      HostName git.com
      IdentityFile ~/.ssh/id_rsa.github
      IdentitiesOnly yes 
      AddKeysToAgent yes

And, of course, I have ~/.ssh/id_rsa.github and ~/.ssh/id_rsa
All looking fine, but last command

  git pull --rebase origin dev git@gitserv:<company>/<repository>.git

don’t working, ask login/password and than said

  remote: Support for password authentication was removed on August 13, 2021.

I don’t understand my mistake, what I doing wrong?