How to change the “partner_to” tag and send email to more partners?  

CODE

I inherited the template and changed “partner_to” and “subject”, the subject changed, but not the “partner_to”.

NOTES

• I added xml file in manifest
• I also tried:
• • {{str(object.mapped('my_partner_ids.email') if object.my_partner_ids else object.mapped('my_partner_ids.email')).replace("'","") }}
  • {{ ', '.join(object.mapped('my_partner_ids.email')) if object.my_partner_ids else '' }}
  • {{object.mapped('my_partner_ids.email')}}

SOURCES

Link 1 Link 2 Link 3

What am I doing wrong; What am I missing?