@ElvisHerrera - Thanks for reaching out to us.
Per your comment, I believe you have followed the steps correctly to establish the connection between the map web part and the list web part. After setting up the connection, you can use the "Validate" button to see if there are any matching features/records. Even otherwise, if there are no matching features/records, you should still see a toast message displayed at the bottom right corner of the map. The toast message will indicate if there are matching records or "no matching records".
I am sharing some links from Esri ArcGIS blogs and also the blogs from Esri Community.
You can enable notifications in Esri Community (ArcGIS for SharePoint Community) so that you get notified whenever we post new blogs.
I have also shared the link to a blog which explains the web part connectivity between the ArcGIS for SharePoint app and custom apps that can be built on the client-side to interact with the map web part. With custom or 3rd party apps, you can establish a two-way communication between your custom web part and the ArcGIS web part.
We are here to help, so, feel free to reach out to us if you are still experiencing any issues while setting up the web part connectivity or if you have any questions related to the ArcGIS for SharePoint app.
Esri ArcGIS Blog explaining the list to ArcGIS web part connectivity - https://www.esri.com/arcgis-blog/products/esri-maps-sharepoint/mapping/dynamic-mapping-with-sharepoi...
Please refer to the " ArcGIS web part as a Consumer” section - https://community.esri.com/t5/arcgis-for-sharepoint-blog/using-dynamic-data-extensibility-feature-to...
ArcGIS for SharePoint blog site - https://community.esri.com/t5/arcgis-for-sharepoint-blog/bg-p/arcgis-for-sharepoint-blog
Thanks & Regards,
Raaj