Efficient way to collect emails for whitelist for paid app

I am selling an app and once organisations have paid for X people to have access I want to efficiently collect the emails for those who are to access the app.

I considered google forms; whilst this works for me - it will be annoying for customers who have say bought 20 apps to have to fill out the form 20 times and put in their company and customer number.

I tested putting multiple emails into one question on google forms and you get messy results.

I will sell the app via my website and am looking for ideas to efficiently collect the emails to copy and paste into the whitelist. All ideas welcome

Possibly telling them to send a text file to you that contains all emails that will get access to the app, and then paste it into the sheet?

Thanks for the idea. Thats a possible option. I’m hoping for a solution which removes/minimises manual steps

I would probably have one text entry component for emails. Have the user enter emails delimited by a comma. The perform a split function in the sheet to split the list of emails on the comma and fill an array of multiple email columns. Set these column headings up as an array, (Email 1, Email 2, Email 3, etc). The only problem is you will have to establish a maximum number of emails, whether it’s 20, 50 or 100 columns.