Your sentence seems a bit unclear. Are you trying to say something like:
"If you missed this opportunity once, don't miss it this time"?
Here’s a clearer version depending on your intent:
Motivational tone:
"If you missed this chance before, make sure you don't miss it now!"
Warning tone:
"You missed it once—don’t let it slip away again."
Feel free to tell me more about what you're trying to say, and I’ll tailor it better!
