The Network Analysis tools in the Ready To Use Tools gallery have been deprecated and removed from the Ready To Use Tool gallery in ArcGIS Pro 3.0. Network analysis can be performed with an ArcGIS Enterprise or ArcGIS Online routing service in ArcGIS Pro using network analysis layers. The workflow is the same as when using a network dataset on disk.
These tools were originally ported from ArcMap, where they were the only way to perform network analysis using a routing service. However, the standard network analysis workflows in ArcGIS Pro seamlessly support routing services with no need for special tools. When creating a network analysis layer in ArcGIS Pro, choose either a network dataset or a routing service as the layer’s network data source. The Ready To Use Tools are now outdated and no longer needed.
Users in ArcGIS Pro 3.0 can carry out Network Analysis workflows from the Network Analysis gallery found on the Analysis tab.
To create a single geoprocessing tool similar to the now-deprecated Ready To Use tools, create a model tool following the tutorial: Create a model for route analysis or create a script tool using the arcpy.nax Python module, as described in: Perform network analysis