6 different clients- Same Item want- What to purchase- Extended or Regular License ...?

I am a freelance app developer, I have 6 different clients, they want same eCommerce app with little modification, can I buy that item with an extended license. Then I will do the desired modification as per respective clients’ needs and sell that product to them. Please clear my doubt. or I do have to buy 6 different regular licenses.

There is no multi use license - each client will require a new purchase

You can’t. Single extended lisence for single product.

Please refer the article