Deductions & credits

I went over this past year by $136.50. On my HSA Excess Contribution form, I put that amount on my excess amount. Now, do I just leave the “earnings on Excess” blank or put $0 there?? The answer I am replying to said to let the HSA custodian calculate the earnings, but when I called HSA, they told me they can’t tell me what to put there. So do I just leave the earnings on excess blank?? Thank You in advance for your response!!