Explanation:

Box 1: Set CsOnlinePSTNGateway
* Set CsOnlinePSTNGateway
Modifies the previously defined Session Border Controller (SBC) Configuration that describes the settings for the peer entity. This cmdlet was introduced with Microsoft Phone System Direct Routing.
Syntax
Set-CsOnlinePSTNGateway
[[-Identity] <string>]
[-BypassMode <string>]
[-Description <string>]
[-Enabled <boolean>]
[-FailoverResponseCodes <string>]
[-FailoverTimeSeconds <int>]
[-ForwardCallHistory <boolean>]
[-ForwardPai <boolean>]
[-GatewayLbrEnabledUserOverride <boolean>]
[-GatewaySiteId <string>]
[-GatewaySiteLbrEnabled <boolean>]
[-InboundPstnNumberTranslationRules <Object>]
[-InboundTeamsNumberTranslationRules <Object>]
[-MaxConcurrentSessions <int>]
[-MediaBypass <boolean>]
[-MediaRelayRoutingLocationOverride <string>]
[-OutboundPstnNumberTranslationRules <Object>]
[-OutboundTeamsNumberTranslationRules <Object>]
[-PidfLoSupported <boolean>]
[-ProxySbc <string>]
[-SendSipOptions <boolean>]
[-SipSignalingPort <int>]
[-WhatIf]
[-Confirm]
[<CommonParameters>]
Box 2: -OutboundPSTNNumberTranslationRules
Assigns an ordered list of Teams translation rules, that apply to PSTN number on outbound direction.
Incorrect:
* -OutboundPSTNNumberTranslationRules
Assigns an ordered list of Teams translation rules, that apply to PSTN number on outbound direction.
* SET CsHybridPSTNApplience
Use the Set-CsHybridPSTNAppliance cmdlet to modify an existing Skype for Business Cloud Connector Edition appliance's attributes.
Note: This cmdlet will be deprecated from Teams PowerShell Module.
Syntax:
Set-CsHybridPSTNAppliance
[-MaintenanceMode <Boolean>]
[-MediationServerGruu <String>]
[-Identity] <XdsGlobalRelativeIdentity>
[-Tenant <Guid>]
[-Force]
[-WhatIf]
[-Confirm]
[<CommonParameters>]
* Set CsHybridPSTNSite
Use the Set-CsHybridPSTNSite cmdlet to modify an existing hybrid public switched telephone network (PSTN) site's attributes.
Note: This cmdlet will be deprecated from Teams PowerShell Module.
Syntax
Set-CsHybridPSTNSite
[-Identity] <XdsGlobalRelativeIdentity>
[-Tenant <Guid>]
[-EdgeFQDN <String>]
[-EnableAutoUpdate <Boolean>]
[-BitsUpdateTimeWindow <Int32>]
[-OsUpdateTimeWindow <Int32>]
[-Force]
[-WhatIf]
[-Confirm]
[<CommonParameters>]
* Set CsOnlinePSTNUsage
Modifies a set of strings that identify the allowed online public switched telephone network (PSTN) usages.
This cmdlet can be used to add usages to the list of online PSTN usages or remove usages from the list.
Syntax:
Set-CsOnlinePstnUsage
[[-Identity] <string>]
[-Usage <Object>]
[-WhatIf]
[-Confirm]
[<CommonParameters>]
Reference:
https://learn.microsoft.com/en-us/powershell/module/skype/set-csonlinepstngateway