You can embed a Home Page or Event Signup Sheet using an iframe tag. For security reasons, embedding is allowed only in:
the website domain entered in the "WEBSITE" field under Organization > Organization Details > Account (for example, mysite.com)
any additional domains added in the "WEBSITE(S) ALLOWED TO EMBED HOME AND EVENT PAGES" field under Organization > Organization Settings > Display/Layout
Please be sure to fill the "WEBSITE" field as a minimum before embedding any ivolunteer pages in an iframe.
The iframe tag has several options that you may review here. You can also search for "iframe generator" in your favorite search engine to get copy-and-paste code with the options of your choice.
NOTE: In Wordpress's Gutenberg editor, you must use a "Custom HTML" block instead of an "Embed" block to embed an iframe.