CreatePnPPackage.ps1

# Make sure all relative paths mentioned in the XML are valid related to the location of the XML file
$pnpTemplate = Read-PnPTenantTemplate -Path myTemplate.xml
# If the XML is invalid, you will have an error here
# Read-PnPTenantTemplate : The element 'AppCatalog' in namespace 'http://schemas.dev.office.com/PnP/2020/02/ProvisioningSchema' cannot contain text. List of possible 
# elements expected: 'Package' in namespace 'http://schemas.dev.office.com/PnP/2020/02/ProvisioningSchema'.
# At line:1 char:16
# + $pnpTemplate = Read-PnPTenantTemplate -Path myTemplate.xml
# +                ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
#     + CategoryInfo          : SyntaxError: (:) [Read-PnPTenantTemplate], XmlSchemaValidationException
#     + FullyQualifiedErrorId : TEMPLATENOTVALID,SharePointPnP.PowerShell.Commands.Provisioning.Tenant.ReadTenantTemplate
# If the XML is valid, the $pnpTemplate contain the template object
###################################################################
# $pnpTemplate
# Parameters           : {[TenantName, contoso], [SitePath, SiteDesignsStudio], [lcid, 1033], [TenantId, ]}
# Localizations        : {}
# Tenant               : OfficeDevPnP.Core.Framework.Provisioning.Model.ProvisioningTenant
# Version              : 0
# Author               : Yannick Plenevaux
# Generator            : Manual
# Description          : A Tenant template to install Site Designs Studio V2 solution
# DisplayName          : Site Designs Studio V2
# ImagePreviewUrl      :
# Connector            : OfficeDevPnP.Core.Framework.Provisioning.Connectors.FileSystemConnector
# Templates            : {SITE-DESIGNS-STUDIO-V2-APP}
# Sequences            : {MAIN-SEQUENCE}
# Teams                : OfficeDevPnP.Core.Framework.Provisioning.Model.Teams.ProvisioningTeams
# AzureActiveDirectory : OfficeDevPnP.Core.Framework.Provisioning.Model.AzureActiveDirectory.ProvisioningAzureActiveDirectory
# Drive                : OfficeDevPnP.Core.Framework.Provisioning.Model.Drive.Drive
# ProvisioningWebhooks : {}

Save-PnPTenantTemplate -Template $pnpTemplate -Out myPackage.pnp