I would like to still specify a pg version so I don’t have to go and change every single project I got any time a pg update comes on.
For Auth0 Node.js sandboxes, you can specify the version using the package-name@x.y.z format:
const { Client } = require("pg@8.7.1");
Auth0 only provides very specific versions for Node.js modules with 8.7.1 being the latest version available. If you want to use older versions on Auth0 sandbox environments, they are documented on Can I Require?.