New feature: You can now pass the icon_url= parameter to stripe.checkout.get_token() and stripe.checkout.charge().
For example, if you have an asset in your app called logo.png:
stripe.checkout.charge(amount=999, currency='USD',
icon_url=anvil.server.get_app_origin()+"/_/theme/logo.png")
Hat-tip to @neriksen85, who used his support agreement to prioritise this feature. If you want to have more influence on the Anvil roadmap, drop us an email at support@anvil.works.