Define Custom <A> Attributes for link within Rich Text CMS Item?

Is it possible to define custom A attributes for links in a rich text field in a CMS item?

I’m trying to create a link within some blog post text that triggers a sumome opt in modal.
This is what I need to link to. As far as I can tell, I can’t select text in a rich text field and link to this, because I don’t have access to the custom A attributes.
<a data-sumome-listbuilder-id="c7610445-4a89-4ae5-b2f9-0709f91c5721">Click Here</a>

Any tips? Am I just missing something?

Thanks for the help!

Here is my public share link: LINK
(how to access public share link)

No, you will have to use Embed Code component for this.