Wrap around sequence - so close!

I get this works. Creates the sequence and pads out to three characters. perfect.

For the life of me I can’t work out why it works. Maybe I am missing something in my JavaScript knowledge, maybe I can’t see the wood for the trees so any help would be appreciated.

I simply want to repurpose this to loop round from 01 to 99 and loop back to 01. I have tried to modify the line in many ways but nothing seems to work. What am I missing?

Many Thanks

I have sorted this thankfully. I simply read the last element as adding “1,000” and it’s just adding “1” and the “000” appears to be the wrap.

Thanks.