We have following web-service which returns different versions of the same spreadsheet depending on the parameter department.

https://oaa-functions-test.azurewebsites.net/api/DepartmentsReportViaWebServiceParam?department={{param}}

You can try it yourself.
In order to download the finance report for the Human Resources department, just plug in the parameter department=HR:
https://oaa-functions-test.azurewebsites.net/api/DepartmentsReportViaWebServiceParam?department=HR.
In order to download the finance report for the Research & Development department, just plug in the parameter department=RD:
https://oaa-functions-test.azurewebsites.net/api/DepartmentsReportViaWebServiceParam?department=RD.

We have built an app with id a979f6dc-c6eb-4d89-8ee3-bc2ed7e57625 with this web-service.
You can launch an app on any device where Open as App is installed by following it's special deep link: openasapp://app/a979f6dc-c6eb-4d89-8ee3-bc2ed7e57625. Note that the last part of the link is simply the id of the app, so you can easily create those links by hand for any app. Following a deep link will start Open as App and redirect the user the corresponding app.

When you click on the deep link of the app, you will notice that the only content of the app is the message Please select a Department. This is because the app was built with no specific value for the department parameter. Instead the department parameter was assigned the "magic" placeholder value {{param}}: https://oaa-functions-test.azurewebsites.net/api/DepartmentsReportViaWebServiceParam?department={{param}}. The {{param}} placeholder can be set to any value by appending it to the deep link of the app. Like follows:

In order to start the app with department=HR, use following link: openasapp://app/a979f6dc-c6eb-4d89-8ee3-bc2ed7e57625?param=HR
In order to start the app with department=RD, use following link: openasapp://app/a979f6dc-c6eb-4d89-8ee3-bc2ed7e57625?param=RD