I just purchased storage space and it’s not showing

It is not possible to buy more storage for an iPhone; it will never have more than it did when you bought it. What you bought is iCloud+ storage that is used for backing up and also for syncing to other devices. Here is an explanation→What's the difference between device storage and iCloud storage? - Apple Support

iCloud+ has 2 independent functions. iCloud backups, and iCloud sync. It’s confusing because they both have the same name prefix. But they have no connection with each other. Go to Settings/[your name]/iCloud. You will see a bunch of switches (with iOS 16 also tap Show All). When you turn on a switch that data type will sync to iCloud. If you do this on multiple devices that share an Apple ID the selected data will sync to all of those devices. 

You can also turn on iCloud Backups. This will back up your phone every night if the phone is plugged in, connected to Wi-Fi and locked.

But note that anything that you sync by the first method will be excluded from the iCloud backups.

I just purchased storage space and it’s not showing

I need the storage space that I just paid for

Check tomorrow again, to day is not a business day.

If you have upgraded iCloud+ plan, once your request for iCloud+ plan has been activated, you should receive an invoice in your email box.

Check -> Go to -> Settings -> your name -> iCloud -> if you see 50 GB (or 200 GB or 2 TB) then you have an iCloud+ plan subscription.

If you have an iCloud+ plan subscription, you will receive a monthly bill from Apple, check your email box.

See also the following Apple articles:

How to use iCloud on iPhone -> How to use iCloud on iPhone – Apple Support (UK)

Manage your iCloud storage -> Manage your iCloud storage - Apple Support

See:

If you bought iCloud extra storage (it might take some hours before you see the extra storage), contact Apple and explain your problem:--> Contact Apple for support and service

Regards

Giulio