Is it permissible for me to request interest from someone who converted to Islam after repaying a debt?

Assalamu alaikum / Hello, I had a situation where someone caused significant damage to my apartment while staying with me as a roommate. They initially promised to cover the costs but didn't, and since they had no insurance, I had to pay out of my own pocket. This put me in a tight spot financially, affecting some personal projects at the time. Years later, they embraced Islam and reached out to me, admitting it was wrong not to pay earlier and committed to reimbursing me. They gradually sent the money, and recently completed the full payment for the repair costs. Now, given the time it took (around 8 years) and inflation eroding the value of that money-we're talking a few thousand euros-I'm thinking about asking for interest to cover my losses. As the person is now Muslim (I'm not), I'm wondering: would it be against Islamic teachings for them to pay that interest? I’d appreciate any insights, as I don’t like confrontations but feel this is worth considering.