I filed my 2024 tax return & received a refund. I now am filing an amended return which will result in a lower refund amount. How do I reflect this on the amended return?

You will still get the refund from the first original return or still need to pay the first tax due.  In fact you should not even amend until the first return has fully processed and you get the first refund or your tax due payment has cleared.  

Then the amended 1040X return is only for the difference you get back or owe.  I think the cover sheet shows what the original return WOULD have been if you did it right the first time.  Ignore the new 1040 that might print out.

Go by the actual 1040X.  Line 18 should be your original refund amount and line 22 should be your additional refund.  If you paid on your original return it will be on line 16.  If there is an amount owed with the amendment, it will be on line 20.