Adding a radio button that increases the price without an app and without product variations

Hello, I am currently using an app for radio buttons where a price is added to the product. Is this also possible without using the app? Without creating variations of the product. It is an extra option that a customer can choose.

For example, the product costs €29.95, but with the extra option of €3.95, the total price becomes €33.90.

Hello @Djoewie
Thank you for submitting your query to the Shopify community. I’d be happy to assist you. Could you please provide the store URL and password (if it’s password-protected) so I can review and get back to you with an update?