In ArcGIS Pro, you can apply many customized symbologies in many ways. There are also many advanced symbology options available. However, if you publish your analysis as web tools, you may lose your symbology settings if you do not follow the best practices.
In this blog, I will introduce you to the four most common ways to apply symbology to your result feature layers, even if you are using a feature class output in some cases. Regardless of which symbology option you choose, the general restrictions still apply. If your symbology is not supported in a map service or a feature service layer, you cannot use that symbology in your result web tool feature layer. Also, if you are using the output feature service, your symbology will not apply.
Control the output symbology of geoprocessing services or a web tools (esri.com)
