Go to your normal page for submission.
Look under your existing code/codes for the create a new proof code button.
Select LLR, it will turn blue.
In the box with none in it, remove none and add the following.
srsieve, 1820

You will see it turns the 1820 into FreeDCPrimeSearch.

Your code should credit
yourself Srsieve FreeDCPrimeSearch LLR