First step: On your SharePoint online site you must create the lists with the fields indicated in the manual.
Second step: You must import the template to your PowerApps, add the name you want.
How to import package:
https://docs.microsoft.com/es-es/powerapps/maker/canvas-apps/help-desk-install#import-the-app
Third step: You must delete the data sources that the template brings by default and create new data sources pointing to the SharePoint lists as it appears in the manual.
for more information:
https://docs.microsoft.com/en-us/powerapps/maker/canvas-apps/add-data-connection
Fourth Step: You must create the galleries and forms again, as it appears in the manual.