Update-FlowConfig.ps1

<# Script to update the configuration (definition) of a Power Automate Flow
# This is an EXAMPLE script and assumes you have a flow with the two placeholder values - amend the parameters and config accordingly #>
 
<#
    .SYNOPSIS 
      Update the config/any hardcoded values in a Flow using placeholders
    .EXAMPLE
     Update-FlowConfig.ps1 -SiteURL 'https://mytenant.sharepoint.com/sites/testsite' -ListID '0d1caedb-c38d-48b0-ba4a-e0fd5218c38b' -FlowPackagePath 'C:\Users\johndoe\Documents\Flows\MyFlow\'
     
     SiteURL : URL to the SharePoint site (assuming a SharePoint trigger)  
     ListID: ID of the SharePoint list
     FlowPackagePath: File path to your extracted Flow package, must be the TOP level folder of the package e.g. "C:\Users\johndoe\Documents\Flows\MyFlow\*"
#>

param(
    [Parameter(Mandatory = $true)]
    [string]$SiteURL,
    [Parameter(Mandatory = $true)]
    [string]$ListID,
    [Parameter(Mandatory = $true)]
    [string]$FlowPackagePath
)

# Set path to definition JSON file
$jsonPath = Get-ChildItem -Path $FlowPackagePath -Recurse -Include definition.json | Select -ExpandProperty Directory

# Append filename
$jsonPath = "$jsonPath\definition.json"

# Get path of top level directory (where flow package is ectracted to)
$topFolderPath = (get-item $jsonPath).Directory.Parent.Parent.Parent.Parent.FullName

# Get JSON content and update placeholders based on parameters
(Get-Content $jsonPath).Replace("{SiteURL}", $SiteURL).Replace("{RequestsListID}", $ListID) | Set-Content $jsonPath

# Re-zip the flow package ready for import - rename the zip file or update script to replace with the name of your flow
Compress-Archive -Path $FlowPackagePath -DestinationPath "$topFolderPath\Flow.zip"