Hi,
I am looking at extending my welcome series and as part of that process wanted to adjust the validity time of the coupon code (Shopify) that I am using. When I went to adjust the length in Klaviyo I got the following message..

I am confused by the part that reads ‘you will need to create new codes for the updated coupon’. I set this up quite some time ago so have forgotten a lot of what I had learned in this regard. I thought the coupons were automatically generated?
Can someone please clarify? Thanks.