Solved
BrianKasingliAccepted solution
Adobe Champion and Community Advisor
February 8, 2023
You can try this to import experience fragment without the <body> and HTML tags,
<sly data-sly-resource="${@path='/content/experience-fragments/my-site/fragment-a/master, selectors='content'}"></sly>
For the CSS and JavaScript, in the XF editable template, page policies where you have configured the client libraries to be used, you should take those and again, refer them in the editable template page where your XF is being served.