What is your technique for following up lead

Hello faslaners, I have been running fb lead ads for a safety training education institute and I have received a ton of leads from it.but the issue is that when ever I follow up with the student they don't convert into customers am I doing anything wrong .
Do you guys have any specific technique that you use to follow up leads and convert them into customers.
I would be great if you guys can help me with it .

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