Prepare your Business
Let's get the important restrictions out of the way. If you're not selling Software as a Service (SaaS), a digital product or a pre-recorded course then you probably can't sell with Paddle. Even if you fall into these two categories you still have to adhere to their Acceptable Use Policy (AUP) but most likely you'll be fine.
Things get a bit more difficult if you are adding digital products to an existing services business. For example you're a developer or designer and want to add some plugins or design template as a digital product. Most likely your website will show the services you offer boldly and the products page may be not immediately visible.
The first step to create a Paddle account includes a textbox ("How are you looking to use Paddle?") that you can use to explain the situation to your best ability. Unfortunately it is restricted to 500 characters, so you'll have to be succinct.
If you're only selling a SaaS or digital product and your website clearly shows them then just explain that.
If you're selling something along side a services business we recommend explaining that in the checkbox ("I have a services business that will not use Paddle, but want to sell XYZ which are digital products on my website (see section/page "XYZ") using Paddle.")
If the verification team is not clear about what you do they will usually ask for clarifying information. Don't worry if that happens, just answer what they the questions they ask and don't give up.