Unable to associate domain

Good morning,

I would like to associate a domain in order to store and recover credentials with the Autofill Credential Provider. I have followed all the steps in the documentation:

https://developer.apple.com/documentation/safariservices/supporting_associated_domains

I have created my JSON file and stored on the /.well-known directory of my domain with HTTPS provided by Let's encrypt certificate.

Code Block {
  "webcredentials": {
      "apps": [ "TEAM_ID.my.app.identifier" ]
  }
}

Code Block
{
"webcredentials": {
"apps": [ "TEAM_ID.my.app.identifier" ]
}
}

Also included associated domains and AutoFill Credential Provider on Xcode capabilities. For Associated Domain included:

webcredentials:mydomain.com

When I try to store my credentials I am always receiving this Error message:

Error Domain=NSOSStatusErrorDomain Code=-25293 ""mydomain.com" failed to approve "TEAM_ID.my.app.identifier"" UserInfo={numberOfErrorsDeep=0, NSDescription="mydomain.com" failed to approve "TEAM_ID.my.app.identifier"}

Xcode 12.4
Working on simulator
Receiving error on my iPhone 11 ios 14.4

I am really desperate with this issue. Any help will be really appreciated.

Thank you