Where is Woocommerce toggle "returning customer" on checkout page ?

Hello,

I have just uploaded 2 different GP stater sites : niche and prime.
For both of them, the address of the checkout page is : https://gpsites.co/seller/checkout/ . On this page a toggle "Returning customer" appears.
When I change the address of the link and put my domain name, this toggle is not on the checkout page anymore !

https://www.screencast.com/t/dks10Fu8

What am I supposed to do, to get it back on the top of the page ?

Thanks a lot for your help.