error in the python code.
my environment python 3.10.4
your code:
def sendsimplemessage():
return requests.post(
"https://api.mailgun.net/v3/m.tymbrel.com/messages",
auth=("api", "ENTERAPIKEYHERE"),
data={"from": "Mailgun Sandbox postmaster@m.tymbrel.com",
"to": "D4D Shared Login cmsi@cmsintelligence.com",
"subject": "Hello D4D Shared Login",
"template": "pvhospital_performance",
"h:X-Mailgun-Variables": "{"test": "test"}"})

I modified the code that working for me:
def mailgunTempApi(receivers,subject,fromwho,apikey,cc=None,text="",html="",template=None,mailgunVariables={},attachments=None, subdomain=''):
"""
This function takes in a list of email addresses, a subject line, an API key, a list of CC email
addresses, a from email address, a template name, a dictionary of variables to pass to the template,
and a list of attachments. It then sends an email to the list of email addresses using the Mailgun
API

:param receivers: <List> list of email addresses to send to e.g. ['abc@abc.com', 'bcd@abc.com']
:param subject: <String> The subject of the email
:param fromwho: The email address that the email will be sent from, e.g. '"test sender" noreply@m.com '
:param apikey: <String> the private api key for the mailgun account
:param cc: <List> list of emails to cc e.g. ['abc@abc.com', 'bcd@abc.com'] (Optional)
:param text: <String> default "" The text version of the email (Optional)
:param html: <String> default "" The HTML body of the email (Optional)
:param template: <String> The name of the template you want to use, f
ind on https://app.mailgun.com/app/sending/domains/<subdomain>/templates (Optional)
:param mailgunVariables: <Dictionary> a dictionary of variables that will be passed to the template
see https://documentation.mailgun.com/en/latest/user_manual.html#batch-sending-1
(Only use when template has variables in html e.g. plain text: {{ emaildate }} or emmbedding html: {{{ <p>a tag here</p>}}})
:param attachments:<List> a list of file paths to be attached to the email (Optional)
:return: The response object. Can help identify whether the email send successfully or not.
e.g. use response.status_code or reponse.content (Optional)
"""
import requests, json
receiver = ','.join(receivers)
if cc:
cc = ','.join(cc)
headers = {
'Authorization': f'Basic {apikey}',
}
files = {
'from': fromwho,
'to': receiver,
'cc': cc,
'subject': subject,
'text': text,
'html':html,
"template": template,
"h:X-Mailgun-Variables": json.dumps(mailgunVariables),
}
for i, attachment in enumerate(attachments):
files[f'attachment[{i}]'] = attachment

response = requests.post(f'https://api.mailgun.net/v3/{subdomain}/messages', headers=headers, files=files)
return response

In our SaaS platform, we have hundreds of events that trigger an email notification. Each email notification uses a different template that has different content and layouts. But they all share the same header, footer and styling.

It would be nice if we could either nest templates into other templates (having one global Layout template with different content for each template) or have a component that we can import into templates, such has being able to create a component for the header and one for the footer, then import them into a template.

It'll allow us to edit the header or footer in one area without having to open hundreds of templates to update our header, for example.