Purchase links

Hello,
I have a big problem with the purchase link.
Normally, as soon as the customer places the order for a domain name, with a specific tld, it should directly send it back to WHMCS already indicating the domain and he just has to continue.
But I have tried several types of links, without success: either I am sent directly to the web hosting order page, or I am sent back to the domain entry page for the search.

Which is the right purchase link?
Thank you

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