How can I use my feature layers from my server with web appbuiler app without uploading my layers to my esri account?

[BarboraBorosova]

I just create a web app buid map and feature layer I want to add separately from another server. 

[MichaelMiller2]

You can add content to a AGOL map via the rest endpoint from your ArcGIS Server. Use Add > Layer from Web, copy and paste the URL and away you go.

[JayantaPoddar]

You could opt for Portal for ArcGIS, which is an in-house cloud. All the shared data would be stored in your organization's storage/premises.

About Web AppBuilder for ArcGIS—Portal for ArcGIS (10.5) | ArcGIS Enterprise 

[DerekLaw]

Hi Barbora,

You could just use an "empty" web map as the starting point for your web app, then use the Add Data widget to add your web services.

Hope this helps,

[RebeccaStrauch__GISP]

If you are using the web AppBuilder developer edition, check out LocalLayerWidget and AccessifizrWidget‌  

this and other widgets and related blogs can be found /blogs/myAlaskaGIS/2016/03/09/web-appbuilder-developer-edition-customization-resource-list?sr=search...