How do I remove the "one-time purchase" option from my auto-charging widget?

To remove the one-time purchase option from the product, you have to go to your Shopify Admin -> Products -> click on a product -> scroll down to the Purchase options card -> check the box in front of the "Only show this product with these purchase options" label. 

If this option still shows up after you do that, then you might simply have to drag and drop the widget into your theme. You can do this simply by following our tutorial here: https://www.sealsubscriptions.com/tutorials/manual-installation