Populate word document

[jk213]

Hi All,

i am currently building a workflow where in i am populating a word document through the premium connector. i was able to successfully create the file. Now, i have an issue with the scenario where if i would want to update that file which was created earlier with populate word document action how can i do that. 
i am able to get the file properties and also i am trying to use that action to populate the updated file but i can't seem to see the columns that i need to update. Below is a snap of my flow

How can i update the already created file with new values from the list from the populate word template action.

Also, i have one more question. I am using a PowerApps button to run the flow. This flow will only be triggered by 2 users through the button. 

so my question is will all the users will be requiring a P1 premium license or just the 2 users who will trigger the flow will require the license?

Any help will be appreciated. Really Urgent!!