You'll report that on the same line for Mortgage - banks, etc. (Form 1098) [Adjust].

You've probably confused this with seller-financed mortgage.

Generally, if your client received the loan from a lender and paid $600 or more in interest during the year, the lender is required by law to issue a 1098.  It does not sound right if the lender is a bank and it did not issue a 1098, assuming the interest was at least $600.