Elias here with Shopify Support. Thank you for reaching out!
Since you're using a Shopify-supported theme, hiding the prices of sold out items may be something that our Theme Support team can help you with. As this type of customization is supported by our design policy and, if your store is subscribed to a plan, you're eligible to use the complimentary design time included with your plan for this customization request.
To help get your customization request started, I've sent an authentication email to the registered email we have on file. Please check your inbox/spam folders and reply to it. Once I've received your confirmation, I'll be able to move forward with the next steps.
Looking forward to hearing from you!
@shop-kiyo please add this css to the very end of your theme.scss file and check
It looks like our Theme Support team has completed your customization request. Did you receive a follow-up email from one of our Theme Support Specialists?
If you have any other questions on this topic, please don't hesitate to let me know.