Add warning for custom databases (#1383)
Add warning for custom databases (#1383)

Add warning that in case of custom DB the user should first check if the user exists and then invoke the API.

Also, removed some spaces in an attempt to fix the request's postData that are currently not displayed.
sandrinodimattia/docs,khorne3/docs,Annyv2/docs,Catografix/docs,jeffreylees/docs,khorne3/docs,jeffreylees/docs,auth0/docs,yvonnewilson/docs,Catografix/docs,auth0/docs,Annyv2/docs,Catografix/docs,hamzawi06/docs,Annyv2/docs,yvonnewilson/docs,yvonnewilson/docs,khorne3/docs,hamzawi06/docs,sandrinodimattia/docs,hamzawi06/docs,auth0/docs,sandrinodimattia/docs,jeffreylees/docs