Buying /24 subnet from a IP broker

Hey guys,

Our company is thinking on buying a /24 subnet from a IP broker since the datacenter company where we rent our dedicated servers can no longer provide us IP ranges.

Does someone know the process involved on this? I have registered an account in ipv4.global but Im uncertain on how the IPs are delivered and what needs to be done for our datacenter to allocate this IPs to us? I asked our datacenter and this is what they said:

"We can advertise your IPv4 ranges on our ASN. If you have your own ASN, we can also announce the ranges. Do you wish for us to advertise or announce your IP ranges?"

Do I need to own an ASN? What is the difference?

Any help will be highly appreciated!

Thanks and stay safe!