I have received this e-mail from GitHub:
You recently used a password to access the repository at languagetool-org/languagetool with git using SVN/1.14.0 (x64-microsoft-windows) serf/1.3.9 TortoiseSVN-22.214.171.124885.
Basic authentication using a password to Git is deprecated and will soon no longer work. Visit https://github.blog/2020-12-15-token-authentication-requirements-for-git-operations/ for more information around suggested workarounds and removal dates.
The GitHub Team
What do I need to do?