Activiti REST API CORS error after configuration

[kinjal]

I have set up project to new system where i am using activiti rest api , to configure activit i have used activiri-rest.war and activiti-explorer.war files it has beed deployed successfully to wildfly and DB connect ion is also tested.

while accessing activiti rest API a i am getting CORS error , No 'access-control-allow-origin' header is present on the requested resource'

i have not modified anything in code from fron-end it is working file in my old system, this issue came in while configuring project to new system. 

what can be the reason behind issue ?

Thanks for any guidance.   

[sanjaybandhniya]

From where are accessing API? Any UI like ADF?