save content of inner html as a html file in angular

I’m using this innerHTML to show html form in out angular component

this.html = this.sanitizer.bypassSecurityTrustHtml(
      '<iframe width="100%" height="800" src="assets/template_forms/registration_form.html"></iframe>',
    );

HTML

<div [innerHtml]="html"></div>

Save

form is being rendered now after entering the values need to save updated content of that whole form in html format in the same assets folder.