Hello,
As detailed on the documentation page (https://www.phpdocx.com/htmlapi-documentation/html-standard/insert-image-Word-document-with-HTML), to insert an SVG image or content, the PHP ImageMagick extension must be installed and enabled and the file to be added must have the "svg" extension.
Also, please note that the "type" attribute is unavailable in img tags (https://www.w3.org/TR/2011/WD-html5-author-20110809/the-img-element.html).
Regards.