Hi - is possible in any way to connect the HTML window to data base?
Yes, there is, but you cannot do it directly, like you can connect a text field to a database. You have to use a step in between, called Messaging. You store something (like a link or HtML), in your DB and if you want to use that in the html-component, you send this content with a message. Any result from the component you message back. Look here: https://support.wix.com/en/article/working-with-the-html-component-in-wix-code