Bubble's built-in Twitter plugin was built for an earlier version of the Twitter API. Twitter has since moved to API v2 with updated access tiers, and the plugin isn't compatible with the free or basic developer plans. This causes an error when you try to set up OAuth through the plugin.
What you might notice
An error appears saying "you currently have access to a subset of Twitter API V2 endpoints and limited v1.1 endpoints" when attempting to authenticate
The OAuth flow through Bubble's Twitter plugin doesn't complete
Workaround
Browse the Plugin Marketplace for a community-built plugin that supports Twitter's API v2
Use the API Connector to set up a direct connection to Twitter's API, which gives you full control over how you integrate Twitter features into your app