Too many external scripts. Try to put all the scripts into 1-2 external files.

[Acorn]

How can I do this on Xara Web Designer Premium 18.0.0.61670 DL x64 Mar 22 2021 How can I access the html to edit this?

You can't. You don't.

A number of the JS & CSS files used in a Xara design are regenerated each design change.
They are included through specific <link> & <script> calls.

If you have produced your own or used third-party widgets, some of these could be merged but you really need to know what you are doing.

Acorn