remote: Support for password authentication was removed on August 13, 2021. Please use a personal access token instead.
remote: Please see https://github.blog/2020-12-15-token-authentication-requirements-for-git-operations/ for more information.
https://github.com/(ユーザ名)/(リポジトリ名).gitになってたところを
https://(アクセストークン)@github.com/(ユーザ名)/(リポジトリ名).gitにしたらプッシュできた。