Deepnote has native SQL cells for PostgreSQL integrations. Give them a try!

To add a connection to PostgreSQL, go to Integrations via the left sidebar, create a new PostgreSQL integration and enter credentials:

Don't forget to connect the newly created "PostgreSQL" integration in the Integrations sidebar.

Whitelisting the Deepnote IP address for security reasons

If your connection is protected, you might need to whitelist Deepnote's IP adressed. Read more here