Try to follow the doc: https://keenthemes.com/metronic/?page=docs§ion=angular-mock-backend. You should change src/app/modules/Auth/_redux/authCrud.js file with your own API URLs. Overall logic are placed here: src/app/modules/Auth/_redux/authRedux.js">src/app/modules/Auth/_redux/authRedux.js During the application initialisation we are checking authorization through AppInit: src/app/modules/Auth/_redux/AuthInit.js.
Also, you can describe your case in details, maybe it would help better understand how to help you.