Microsoft Power app and Power Automate Staff Expense App

Hello, I'm looking for someone who has done this work before, I'm planning to create an expenses app that employees can do the following:
The employee will open the app, no need for period or month selections, as the date will be depending when they buy the items.
Enter the date of the item they bought, select the line item for expenses, enter the amount with GST, and also enter the amount of the GST from the item (Auto calculated) based on the total of the item. but can be also overwritten by the employee if a different amount was.
Attached is a picture or pdf file of that item
---------- Done --------------
then the employee keeps adding items on the go.
Each item does not need to be approved. as all items are approved by the manager before they go and buy. but we need to send the expense sheet or request with the total item bought to the supervisor (will approve) then the supervisor will either send it to Finance for processing if less than 1000 or if the amount is more than 1000 it will go the above manager for approval and once it's approved it will go to Finance for processing

What I'm looking for is easy less or non-code at all. I will be using a testing show-and-tell platform that I have with Microsoft. and copy the final work to my company.

The developer must walk me through the development stages and provide me with how I can replicate the work on the live site. also will need to help me understand how to develop different forms, that may have smaller concepts.
Please let me know.