Send Registration Emails To Non-Administrator role / Rules Data Selector By Role
I highly recommend you don't do this, but if you put the following code into a file rules/src/Plugin/RulesAction/SystemSendEmailToRole.php then it'll give you a new action where you can enter the machine name of the role you want to send to (e.g. "myadmins") and it'll do what you want (I tested it, it works though no money back &amp; no guarantee!):

https://gist.github.com/stevepurkiss/9b36eb79311d16c65e8d4d0ba9f1854b

All I did was copy the send email action, swap the 'to' string field to 'role', then load up all user ids with that role, foreach loop through them and insert their email address one by one as it loops through.

Looks like it could be extended to cope with multiple roles like the original code copes with multiple email addresses but this is the best you get in the half hour since I saw your post, and for free ;)

Of course it'll break if you update rules, there's no guarantees, but I did a bit of Rules 7->8 upgrading actions a couple of years back so know my way around a little. Not a lot, but a little ;)

Please also consider supporting rules too, this stuff doesn't appear from thin air, it's a collaboration!

HTH

Steve