Service Request custom thank you message did not work

Hello here, We are starting using Service Desk for some of our customers.
But the acknowledgment is not so friendly " Thank you for your support request! We are tracking your request as ticket #27, and will respond as soon as we can."

So I wanted to create a custom message and followed these instructions :
Create a .gitlab/issue_templates/ at repository level

And at setting>>general>>srvice desk in the Template to append to all Service Desk issues section I choose tank_you form message.

But when creating new service des issues the user still receive the old message.

What have i made wrong ?
Can somebody help me ?