Won’t let me purchase transactions to progress the mission.
Which stage of the mission are you on? They don’t all need to be purchased - see:
I’m stuck on the first purchase. It won’t let purchase the upgrade and it’s blocking Lana from progressing.
It’s possible there’s still one thing to destroy before the script advances. Check your minimap carefully for any stray markers. Otherwise, you may need to try a save-quit-restart.