1. We need to export our flow solution as ZIP package, and extract it's contents
2. Next step we will need to find our flow definition in json format. In my case it's path: 'Microsoft.Flow' --> 'flows' --> 'folder with flow ID' --> 'definition.json'
3. Open 'definition.json', apply pretty print in your favourite text editor (Shift+Alt+F) - I use Visual Studio Code
4. Find section where there are properties of trigger action of your flow, and change order of these properties
5. Save 'definition.json', copy modified file to original exported ZIP and replace it in the same path
6. In Power Automate, import your modified ZIP package (remember to choose update, not create new flow with that ZIP)
7. If import succeeded, test your flow, and you should have correct order of inputs in your action 🙂