Integration of Angular 9 front end to node Js back end server program

We have created a angular 9 front end for an IoT application , we need that integrated with already existing node js server back end , the server back end has data existing in certain data structures . These have data structures need to be transformed and fed to the front for data updates , location /map updates etc.. Additionally, certain data’s entered in the front end need to stored in the node js backend via api’s which need to built.