Display page not found. Please check the page exists

Hello,
My contact form folder have a subfolder (email send). In the option of the subfolder I have:
Display template: form

It seem to be all I need to have the "email send" page when validating a mail but I alway have the message:
"Display page not found. Please check the page exists."

I don't know what I miss.
Thank for your help

@cvgrenoble, The template of the 'merci' page must be 'formdata'.

See https://learn.getgrav.org/17/forms/forms/example-form :

Now inside the page folder create a subfolder named thankyou/ , create a new file named formdata.md . And paste the following code into the file:

---
title: Email sent
cache_enable: false
process:
    twig: true
---

## Email sent!

I try something like this:

This give me that:

but this is the same problem.

@cvgrenoble, You should use field 'Page Template', but if it doesn't contain 'FormData' in the dropdown, you will not be able to set it in Admin.

You can then only set the filename/template from within the filesystem.

@cvgrenoble,

As said before, if, in Admin, the field ‘Page Template’ does not contain template 'FormData' you will have to create that page manually on the filesystem.

Something similar to the following:

user
└── pages
    ├── 01.home
    └── 02.contact
        ├── form.md
        └── thankyou
            └── formdata.md

File formdata.md should then contain something similar to:

---
title: Email sent
cache_enable: false
process:
    twig: true
---

## Email sent!

If you don't know how to create a folder and file on the filesystem, Grav will be a tough journey...

If by "manually" I have to understood to modify something that is on my hard drive, then I can't. No grav cms software are one my hard drive. Everything have been build from the administration panel (https://learn.getgrav.org/17/admin-panel/introduction). And as I say, I make it work in my preview backup.

@cvgrenoble,

And as I say, I make it work in my preview backup.

If your issue has been solved, then please mark the post as such by ticking the 'solution' icon in the lower right corner of any reply that lead to the solution. That may well be your own reply...