How school administrator blocks vpn on school wifi?

That's an option built into their professional network devices.

Changes with each implementation so how is something you ask them directly.

At least you didn't ask "How do I get around that?"

As the title states, from my understanding it's not that "VPN-blockers", like schools or organisations, often block VPN-usage in general.

The way they usually do it is by blocking specific IP addresses, belonging to servers they notice a lot of traffic is coming from to their website (because many people with the same IP are going to their website).

This is how Netflix and other big streaming websites do it for example, I believe.

Hope this is clear.

They don't allow vpn connections. Its a setting in the router. Do your homework instead of trying to play a game....