The Old Testament Law/Covenant still stands today and you have the choice to try to follow it if you want. I don’t see why you would want to because it’s “to be perfect you have to do all this all your life but TLDR you’ve already broken it so it’s impossible and you’re already condemned”. Jesus introduced a new covenant (aka testament, hence “New Testament”, also called “New Covenant” in some bibles) of grace and forgiveness, which is superior to the Old. We don’t ignore the Old as such, we just follow the New because it’s better.