What are you trying to do with your code as note that you can already add EcWid without using code as shown here.
https://support.wix.com/en/article/third-party-app-online-store-by-ecwid
https://support.ecwid.com/hc/en-us/articles/115005874885-Adding-your-Ecwid-store-to-Wix-site
https://support.ecwid.com/hc/en-us/articles/207808335-Ecwid-plans-and-pricing-for-Wix
The same with Facebook, you can do various bits for it without using code, like you have mentioned in your post - add Facebook page like button.
https://support.wix.com/en/article/using-facebook-on-your-wix-site
https://support.wix.com/en/article/adding-and-setting-up-a-facebook-like-button
https://support.wix.com/en/article/adding-and-setting-up-a-facebook-share-button
https://support.wix.com/en/article/facebook-like-button-vs-facebook-page-like-box