Set-SPOTenant: Cannot bind parameter 'SharingCapability'. Cannot convert value "Anyone"

Cannot bind parameter 'SharingCapability'. Cannot convert value "Anyone" to type "Microsoft.Online.SharePoint.TenantManagement.SharingCapabilities". means -SharingCapability got a word that is not one of its enum names. The admin center shows friendly labels; PowerShell needs the internal names:

Set-SPOTenant -SharingCapability ExternalUserAndGuestSharing      # "Anyone"
Set-SPOSite -Identity https://contoso.sharepoint.com/sites/finance -SharingCapability ExistingExternalUserSharingOnly

Reproduce it

PowerShell converts the value before the cmdlet runs, so the error appears without a connection (module 16.0.27709.12000):

Import-Module Microsoft.Online.SharePoint.PowerShell -DisableNameChecking
try {
  Set-SPOTenant -SharingCapability Anyone -ErrorAction Stop
} catch {
  $_.Exception.Message
}

Cannot bind parameter 'SharingCapability'. Cannot convert value "Anyone" to type "Microsoft.Online.SharePoint.TenantManagement.SharingCapabilities". Error: "Unable to match the identifier name Anyone to a valid enumerator name. Specify one of the following enumerator names and try again:
Disabled, ExternalUserSharingOnly, ExternalUserAndGuestSharing, ExistingExternalUserSharingOnly"

The message lists the four valid names.

Admin center label to PowerShell value

The same names are used by Set-SPOSite -SharingCapability and Set-SPOTenant -OneDriveSharingCapability. A site cannot be more permissive than the tenant setting: see SharingCapability.