Every api request session id is changing

my backend is magento 2 with graphql and in front-side we are using next js so my problem is for on every request in api response set-cookie header gives different PHP session id but i have to maintain the same session id. For next js api call we use apollo client. Frontend and backend both are on different domain for example frontend domains is web.magento.com and backend domain is back.magento.com.