Sending bulk emails

I am trying to modify and use the method described in Julian Kirkness's blog article "Sending Bulk Emails in Ninox". For anyone interested, the URL is https://www.onlinedatabase.expert/post/sending-bulk-emails-in-ninox?postId=5cd1989db532380015590a5c.  Thanks to Julian for a great article that helped me get started!

My email addresses are stored in my table Volunteers and I put this code behind the send button:

"-------------------------------------------------------------------------------------------------";
"this code loops through each volunteer whose status is active and sends them an email";
"the body of the email uses the replace function to substitute data from the datbase for the";
"placeholders in the template";
"-------------------------------------------------------------------------------------------------";
let thisList := (select Volunteers where Status = "Active");
let subject := 'Email Template'.'Subject Line';
let body := 'Email Template'.'Email Body';
for thisListPerson in thisList do
let thisBody := body;
thisBody := replace(thisBody, "{Informal Name}", thisListPerson.'Informal Name');
thisBody := replace(thisBody, "{UserName}", userFullName());
sendEmail({
from: userEmail(),
to: thisListPerson.email,
subject: subject,
text: " ",
html: thisBody
})
end;
'Date / Time Sent' := now();
'Sent By' := user()

Nothing happens when I press Send. I am new to coding in Ninox and wonder if someone more experienced can quickly see my error?

Also, how could I modify my HTML body to include a logo image at the foot of the HTML block? I read another post on this but didn't understand the solution. I have the logo on my computer, not currently stored in Ninox.

Thanks in advance for any help!