When authorizing a community connector, an OAuth consent screen may be presented to you with a warning "This app isn't verified". This is because the connector has requested authorization to make requests to an external API (E.g. to fetch data from the service you're connecting to). If you have followed the deployment guide to setup a community connector and are using your own personal deployment you do not need to complete the verification process and instead can continue past this warning by clicking Advanced > Go to {Project Name} (unsafe).
If you are using a community connector that you did not personally deploy it is recommended that you only proceed with community connectors from trusted sources.
For distribution or non-personal use cases the project must eventually go through the verification process to remove that warning and other limitations.
For additional details see OAuth Client Verification.