How to change the notification body from Redmine?

Question

Ruby on Rails

Receive notification from Redmine about new tasks or changes.
It does not look very nice and scares users.
How to make a notification template for yourself?
I know that the file with notification settings is here app\models\mailer.rb.
But it is not clear where in this code you can configure the notification template.
Now the following is coming in the mail:
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Issue #10 has been updated by Redmine Admin.
____________________________________________
• Status changed from In Progress to New
____________________________________________
Error #10: Error_test_1
• Author: Test Tester
• Status: New
• Priority: Normal
• Assignee: Test Testovich
Description.
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I would like to at least translate into Russian and remove / add part of the fields.
Thank you!

Answer 1

https://github.com/redmine/redmine/tree/master/app/views/mailer