Create a file and folder then move created file into that folder

Naligurtan 

List - Test2

Customer: Lookup field to Customers 

Customer Exists: Choice Yes or No 

Library - CustomerFolders

Does the flow run- when an item is created, or modified, or when a condition is met? You'll need the right trigger and maybe a trigger condition.  I set it to manually start and you enter the ID.

Create the content for the file.  We'll use this to create a text file.

Create a variable for the folder path - /DocumentLibraryName/CustomerName

Use a condition to see if the customer exists.  

Check to see if the Customer Exists = Yes

If yes, create the file.

Otherwise, create the folder, then create the file in the new folder.

Hopefully this is enough to get you started.  There is a great Power Automate community here. https://powerusers.microsoft.com/t5/Forums/ct-p/FL_Comm_Forums