Tax Year Prior to 2020: Dependent Care FSA enrollment while spouse was unemployed

I mistakingly signed up for a Dependent Care FSA and received reimbursement when my spouse was unemployed (I did not fully read the rules for eligibility and was unaware of the rules when I filed my claim for reimbursement).  My husband has been actively looking for work but did not earn an income during the time that I contributed to the FSA.  How do I correct this mistake on my tax return so that I am properly paying taxes on the money I was reimbursed?