bitwarden_rs is especially good if you're looking to self host. https://github.com/dani-garcia/bitwarden_rs
Some of the newer premium features, such as SSO integration are under the Bitwarden license, which is more of a visible source license.
If you read through the link you posted and also the FAQ, you'd see that you can only self host the free tier features for free. If you wish to have some premium features or a family sharing feature and want to self host, you still have to pay. My question was about what the OP was using/hosting and the licensing model.