Registration Form Validation

follow the below steps please
1. got to https://sparejo.com/my-account
2. click on RIGISTER button
3. choose “Iam a vendor”
3. fill the email field with wrong format–> ex: “maher”
4. fill all requierd fields
5. click on RIGISTER button
6. it will move the cursor to email field without any error or warning message

yes it will not work becaouse you enter invalid format–>”maher”
if you enter “[email protected]” it will work fine
My Question is: why it does not show any message that tell the user to enter a valid email
If you check the demo, you can see the message for this error that till user to enter right email format

I do not have a problem when a user enter a valid email
my problem is if the user enter invalid email like “maher”, the website does not show any error message for the user, it just focus on email field without any message!!.
please look to attached file

From Dokan demo
which the main plugin of my website
URL : http://dokandemo.wedevs.com/my-account/
I do not know why it does not act like this demo
In my website If someone does not fill the email field and then click on RIGISTER button it will submit the form and then show error message!! why there is no javascript that prevent this behaviour, it should check all required fields before submission

I do not have access now
I will provide you the access