I completed 2022 filing on 2-Feb. On 3-Feb (and everyday afterward) I receive an email saying "...so close...95% complete") and 20% discount. Can I apply this discount?

It sounds like it is a marketing email. If you have already completed and filed your taxes you have nothing to worry about.  The 20% discount is included in the current promotional pricing and not something that can be added after you have filed.