Hi Dimitris,

Thanks for reaching out to us. This would require a custom validation script. Here is the one that you can use 

<script>
window.ameliaActions = {
  customValidation: function (success = null, error = null, data) {
    console.log('customValidation HOOK')
    console.log('------------')
    console.log(data)
    const customValidator = (rule, value, callback) => {
      let pattern = /^\d{10}$/;
 
      if (!pattern.test(value.replace(/\D/g,''))) {
        callback(new Error())
      } else {
        callback()
      }
    }
    data.rules.phone.push({required: false, message: 'The phone number must be 8 digits long', validator: customValidator, trigger: 'submit'})
  }
}
</script>

Custom code needs to be applied to the page where the booking form is. Depending on what you're using (Gutenberg blocks, or some page builder), adding the CSS or JS can be done in a few different ways. 

If you need help with adding custom CSS to the page, please take a look at this article.

If you need help with adding custom JS to the page, please take a look at this article.

Hello Rakinul,

I would kindly ask you to open a new ticket and we will provide assistance there. In that way, issues and questions that are related to different subjects will be in separate tickets so other customers or our support agents can find them easily. 

Thank you for understanding.