What time of day is best? OPK

So I just recently bought a opk and have never tried testing for this before and so I’m wondering what time of day might be best to get a general idea everyday of my lh levels! I believe this app is off for me and the only way to correct it is to test, right!? So that’s what I plan to do. I just wonder if there’s a time of day that gives you the easiest / best results! Please comment to help give me some insight! Af just left a couple of days ago so I know I should start texting lh now. Sorry if any of what I said is confusing I’m not entirely sure the best way to word this..