Hi, @ghenriqueo !
Katy here from Shopify. I hope all is well with you and welcome to our Community here.
I'm sorry to hear that you are having difficulties with this. I can see that the 'add to cart' (adicionar ao carrinho) button is currently placed above the product description, instead of below it. I can certainly understand how you would like this fixed up, to make for a more streamlined and pleasant shopping experience for your customers.
It is however a little difficult to determine the cause of this without a link to your store. Had you made any recent edits to your theme - specifically the product-template.liquid? Or have you added any apps to your store recently? If so, there is always the option to roll back to a previous version of each template. We have info on how to do this here. I would suggest having a look at this first and to revise any edits, if you have made some that is.
As you appear to be using a third party theme, we wouldn't be able to run this by our Theme support here. However, if you could share a link to your store perhaps some of our community members can chime in to help. Alternatively you may like to reach out to the theme developer directly.
Also, I notice that your store is in Portuguese. While you are of course welcome to chat here, you may also like to explore our Portuguese(BR) Community too.
I hope this helps, feel free to let me know if you have any questions at all.