As suggested by @furas, we can use git url.

ubuntu@ubuntu:~/hello$ poetry add scikit-learn git+https://github.com/scikit-learn-contrib/imbalanced-learn.git Creating virtualenv hello in /home/ubuntu/hello/.venv Using version ^1.7.1 for scikit-learn

Updating dependencies Resolving dependencies... (0.1s)

Package operations: 6 installs, 0 updates, 0 removals

• Installing numpy (2.3.2)
• Installing scipy (1.16.1)
• Installing threadpoolctl (3.6.0)
• Installing joblib (1.5.1)
• Installing scikit-learn (1.7.1)
• Installing imbalanced-learn (0.14.dev0 fe591e6)

Writing lock file ubuntu@ubuntu:~/hello$